D1451 radiation curable supercoatings for multi-mode optical fiber

ABSTRACT

The first aspect of the instant claimed invention is a method of formulating radiation curable Supercoatings for application to an optical fiber used in a telecommunications network. A Multi-layer Film Drawdown Method useful in the Method of formulating radiation curable Supercoatings is also described and claimed. Single mode Optical fibers coated with specific radiation curable Supercoatings are also described and claimed.

RELATED PATENT APPLICATIONS

This is a continuation of U.S. application Ser. No. 13/388,726, filed onFeb. 3, 2012, which is the U.S. national phase of InternationalApplication No. PCT/US2010/002720, filed 8 Oct. 2010, which designatedthe U.S. and claims the benefit of priority to U.S. Provisional PatentApplication No. 61/272,596, filed Oct. 9, 2009; U.S. Provisional PatentApplication No. 61/250,329, filed Oct. 9, 2009; U.S. Provisional PatentApplication No. 61/287,567, filed Dec. 17, 2009; and U.S. ProvisionalPatent Application No. 61/363,965, filed Jul. 13, 2010; the entirecontents of each of which are hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to radiation curable coatings for opticalfiber.

BACKGROUND OF THE INVENTION

An optical fiber is a glass fiber that carries light along its length.Optical fibers are widely used in fiber-optic communications, whichpermits transmission over longer distances and at higher bandwidths(data rates) than other forms of communications. Fibers are used insteadof metal wires because signals travel along them with less loss, andthey are also immune to electromagnetic interference.

Light is kept in the core of the optical fiber by total internalreflection. This causes the fiber to act as a waveguide. Fibers whichsupport many propagation paths or transverse modes are called multi-modefibers (MMF), while those which can only support a single mode arecalled single-mode fibers (SMF). MMF generally have a larger corediameter, and are used for short-distance communication links and forapplications where high power must be transmitted. SMF are used for mostcommunication links longer than 550 meters (1,800 ft).

Throughout this patent application, attenuation in fiber optics, alsoknown as transmission loss, is defined as the reduction in intensity ofthe light beam (or signal) with respect to distance traveled through atransmission medium. Attenuation loss coefficients in optical fibersusually are reported using units of decibels per kilometer, abbreviateddB/km.

Attenuation is an important factor limiting the transmission of adigital signal across large distances. Thus, much research has gone intoboth limiting the attenuation and maximizing the amplification of theoptical signal. Empirical research has shown that attenuation in opticalfiber is caused primarily by both scattering and absorption.

In 1965, Charles K. Kao {one of three winners of the 2009 Nobel Prize inphysics for “groundbreaking achievements concerning the transmission oflight in fibers for optical communication”} and George A. Hockham of theBritish company Standard Telephones and Cables (STC) were the first topromote the idea that the attenuation in optical fibers could be reducedbelow 20 decibels per kilometer (dB/km), allowing optical fibers to be apractical medium for communication. They proposed that the attenuationin fibers available at the time was caused by impurities, which could beremoved, rather than fundamental physical effects such as scattering.The crucial attenuation level of 20 dB/km was first achieved in 1970, byresearchers Robert D. Maurer, Donald Keck, Peter C. Schultz, and FrankZimar working for American glass maker Corning Glass Works, now CorningIncorporated. They demonstrated a fiber with 17 dB/km attenuation bydoping silica glass with titanium. A few years later they produced afiber with only 4 dB/km attenuation using germanium dioxide as the coredopant. The achievement of such low attenuations ushered in opticalfiber telecommunications and enabled the internet.

The following U.S. patent is incorporated by reference in its entirety:U.S. Pat. No. 6,014,488 issued on Jan. 11, 2000.

Microbends are sharp but microscopic curvatures in an optical fiberinvolving local axial displacements of a few micrometers and spatialwavelengths of a few millimeters. Microbends can be induced by thermalstresses and/or mechanical lateral forces. When present, microbendsattenuate the signal transmission capability of the coated opticalfiber. Thus for the success of a telecommunications network it is knowneach telecommunications system has a limit to the amount of tolerableincrease in attenuation for optical fiber and that to avoid reachingthat limit it is well to reduce microbending overall because reducingmicrobending, reduces the increase in attenuation.

One of the critical driving forces for the development of optical fibercoating technology is increased user demands on videos. For the existingtechnology of optical fiber coating, 2G network application issufficient. However, the future networks, such as 3G, 4G, and IPTV, highdefinition television (HDTV), video conferencing and other highbandwidth applications will impose a higher requirement for theperformance of optical fiber, therefore the requirement of performanceof the optical fiber coating will become higher and higher.

In order to meet the huge demand of video applications on the internet,the telecommunication network of next generation requires the support oftransmission of greater capacity, longer distance and broader spectralrange, and the performance of the current generation of optical fibersG652 was developed for long haul straight alignment utility; thereforeG562 is not suitable to meet the requirements of Fiber to the Home(FTTH) challenges.

As optical transport of communication signals migrates into homes andMDU's (Multiple Dwelling Units), optical glass fibers are encounteringtighter bends, requiring optical fiber producers to offer G657 Macrobendresistant fibers. At the same time, increasing demands for bandwidth areputting strains on the available margin in deployed networks.

The first generation of radiation curable DeSolite Radiation curableSupercoatings™ (trademark of DSM IP Assets B.V.) for optical fiber aredescribed and claimed in these U.S. Patent Applications, which arehereby incorporated by reference in their entirety: U.S. patentapplication Ser. No. 11/955,935, filed Dec. 13, 2007, published as US20080226916 on Sep. 19, 2008; U.S. patent application Ser. No.11/955,838, filed Dec. 13, 2007, published as US 20080241535 on Oct. 23,2008; U.S. patent application Ser. No. 11/955,547, filed Dec. 13, 2007,published as US 20080226912 on Sep. 19, 2008; U.S. patent applicationSer. No. 11/955,614, filed Dec. 13, 2007, published as US 20080226914 onSep. 19, 2008; U.S. patent application Ser. No. 11/955,604, filed Dec.13, 2007, published as US 20080226913 on Sep. 19, 2008;

U.S. patent application Ser. No. 11/955,721, filed Dec. 13, 2007,published as US 20080233397 on Sep. 25, 2008; U.S. patent applicationSer. No. 11/955,525, filed Dec. 13, 2007, published as US 20080226911 onSep. 19, 2008; U.S. patent application Ser. No. 11/955,628, filed Dec.13, 2007, published as US 20080226915 on Sep. 19, 2008; and U.S. patentapplication Ser. No. 11/955,541, filed Dec. 13, 2007, published as US20080226909 on Sep. 19, 2008.

U.S. patent application Ser. No. 11/955,541, filed Dec. 13, 2007,published on Sep. 18, 2009 as US Published Patent Application20080226909, entitled “D1381 RADIATION CURABLE SUPERCOATINGS FOR OPTICALFIBER” describes and claims Radiation Curable Supercoatings for OpticalFiber as follows:

Supercoatings suitable for coating an optical fiber;

wherein the Supercoatings comprise at least two layers, wherein thefirst layer is a Primary Coating that is in contact with the outersurface of the optical fiber and the second layer is a Secondary Coatingin contact with the outer surface of the Primary Coating,

wherein the cured Primary Coating on the optical fiber has the followingproperties after initial cure and after one month aging at 85° C. and85% relative humidity:

A) a % RAU of from about 84% to about 99%;

B) an in-situ modulus of between about 0.15 MPa and about 0.60 MPa; and

C) a Tube Tg, of from about −25° C. to about −55° C.;

wherein the cured Secondary Coating on the optical fiber has thefollowing properties after initial cure and after one month aging at 85°C. and 85% relative humidity:

A) a % RAU of from about 80% to about 98%;

B) an in-situ modulus of between about 0.60 GPa and about 1.90 GPa; and

C) a Tube Tg, of from about 50° C. to about 80° C.

With the recent launch of the DeSolite Supercoatings™ line of Radiationcurable Supercoatings for optical fiber, by DSM Desotech, seewww.Supercoatines.com it has been reported that use of Supercoatings hasgreat positive effect upon the microbending characteristics of theoptical fiber. Thus using Supercoatings is known to reduce the amount ofmicrobending in an optical fiber and reducing the amount of microbendingreduces the amount of attenuation in the telecommunications network

As the demand for ever increasing bandwidth develops in the internet andcurrent telecommunications devices, the demand for optical fiber that isattenuation resistant will also increase. Thus the demand for radiationcurable Supercoatings will increase. As the demand for attenuationresistant optical fiber and radiation curable Supercoatings increases itwould be desirable to have a method for selecting and formulatingradiation curable Supercoatings for optical fiber.

SUMMARY OF THE INVENTION

The first aspect of the instant claimed invention is a method offormulating radiation curable Supercoatings for application to anoptical fiber used in a telecommunications network, wherein saidSupercoatings comprise at least two layers, the first layer being aprimary coating that is in contact with the outer layer surface of theoptical fiber and the second layer being a secondary coating in contactwith the outer surface of the primary coating, wherein the cured primarycoating on the optical fiber has the following properties after initialcure and after at least one month aging at 85° C. and 85% relativehumidity:

-   1) a % RAU of from about 84% to about 99%;-   2) an in-situ modulus of between about 0.15 MPa and about 0.60 MPa;    and-   3) a Tube T, of from about −25° C. to about −55° C.;    and wherein the cured secondary coating on the optical fiber has the    following properties after initial cure and after at least one month    aging at 85° C. and 85% relative humidity:-   4) a % RAU of from about 80% to about 98%;-   5) an in-situ modulus of between about 0.060 GPa and about 1.90 GPa;    and-   6) a Tube T_(g) of from about 50° C. to about 80° C.;    said method comprising the steps of:-   a) determining the Maximum Acceptable Increase in Attenuation    requirements for the telecommunications network where the optical    fiber will be installed;-   b) determining a Field Application Environment of the Supercoatings    comprising:    -   i) selecting the type of glass being used in the optical fiber;    -   ii) deciding whether the secondary coating of the Supercoatings        will be applied over the primary coating of the Supercoatings        wet-on-dry or wet-on-wet;    -   iii) selecting the type, number of lights and positioning of        lights along a draw tower manufacturing line that are used to        cure the Supercoatings on the optical fiber; and    -   iv) selecting the line speed at which the Supercoatings will be        applied;-   c) formulating a primary coating composition in a liquid, uncured    state;-   d) formulating a secondary coating composition in a liquid, uncured    state;-   e) using a Three-Dimensional Laced Methodology, as shown in FIGS. 2,    3 and 4, of    -   i) testing the primary coating and secondary coating of the        Supercoatings to determine if the Supercoatings parameters 1)        through 6) are achieved; wherein        -   if each and every one of the Supercoatings parameters 1)            through 6) are achieved then proceed to step f); and        -   if each and every one of the Supercoatings parameters 1)            through 6) have not been achieved, reformulate either or            both of the primary coating or secondary coating of the            Supercoatings and repeat step ii) until each and every one            of the Supercoatings parameters 1) through 6) are achieved;            and then    -   ii) verifying the integrity of the reformulation of the primary        coating and the secondary coating of the Supercoatings by        evaluating changes in each formulation relative to the other        formulation and relative to all of the Supercoatings        parameters 1) through 6);-   f) using the results from step e)i) and step e)ii) to finalize the    selection of Supercoatings to achieve the Maximum Acceptable    Increase in Attenuation of the coated optical fiber.

The second aspect of the instant claimed invention is the Method of thefirst aspect, in which the Three-Dimensional Laced Methodology includesusing a Multi-Layer Film Drawdown method to evaluate composite fusedPrimary Coating Layer and Secondary Coating Layer of Radiation curableSupercoatings.

The third aspect of the instant claimed invention is a Multi-Layer FilmDrawdown Method comprising the steps of:

-   a) selecting a substrate for the test;-   b) applying a Primary coating to the substrate using a defined    thickness drawdown bar;-   c) optionally curing the Primary coating;-   d) applying a Secondary coating to the Primary coating using a    defined thickness drawdown bar, wherein the defined thickness of the    drawdown bar to apply the Secondary coating is greater than the    defined thickness of the drawdown bar used to apply the primary    coating;-   e) applying radiation to the multi-layer film sufficient to    effectuate the cure of both the Primary and Secondary into a Fused    Composite film;-   f) removing the film from the substrate; and-   g) evaluating the functional properties of the cured film.

The fourth aspect of the instant claimed invention is a single-modeoptical fiber coated with Supercoatings, wherein said Supercoatingscomprise,

-   a Primary Coating Layer and a Secondary Coating Layer;-   wherein the composition of the Primary Coating layer, prior to    curing, is selected from the group consisting of the formulations of    Examples 1PA2, 1PB3, 1PC1, 1PD5, 2Alpha, and 2Beta;-   wherein the composition of the Secondary Coating layer, prior to    curing, is selected from the group-   consisting of the formulations of Examples 2SA4 and 2SB3 and 3SA1    and 5SA1.

The fifth aspect of the instant claimed invention is a multi-modeoptical fiber coated with radiation curable coatings comprising aPrimary Coating Layer and a Secondary Coating Layer

-   -   wherein the composition of the Primary Coating layer, prior to        curing, is selected from the group    -   consisting of the formulation of Example 1PD5; and    -   wherein the composition of the Secondary Coating layer, prior to        curing, is selected from the group    -   consisting of the formulations of Examples 2SA4 and 2SB3 and        3SA1 and 5SA1.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of historical depiction of formulation diagram forhow typical formulating for optical fiber coatings has beendone—illustrating the prior art. This is a comparative example, not anexample of the instant claimed invention.

FIG. 2 is the first embodiment illustrating the three-dimensional lacedmethodology for formulating radiation curable Supercoatings for OpticalFiber.

FIG. 3 is the second embodiment illustrating the three-dimensional lacedmethodology for formulating radiation curable Supercoatings for OpticalFiber.

FIG. 4 is the third embodiment illustrating the three-dimensional lacedmethodology for formulating radiation curable Supercoatings for OpticalFiber.

FIG. 5 is an illustration of the results of the Multi-Layer FilmDrawdown method showing a colored photograph of a Supercoatings PrimaryLayer, drawn down with a 1.5 mil bar, then a candidate for SupercoatingsSecondary layer, observed as a brown layer, is drawn down over theprimary with a 3 mil bar, and the whole plate cured.

FIG. 6 is Spectra “all”, which shows 4 spectra with a comparableappearance to two sets of two sitting on top of each other.

FIG. 7 is Spectra “Brown” shows the colored secondary portion only, andthe top of the dual drawdown portion. The two spectra match up quitewell.

FIG. 8 is Spectra “for the Supercoatings Primary Layer from Example1PC1” shows the glass side of the dual layer, and the glass side of asingle 3 mil, Example 1PC1 Supercoatings Primary Layer drawdown. Againthe spectra match up very well.

FIG. 9 is a DMA plot of a Flat Film Drawdown of Primary PMoctSupercoatings Candidate, this is a Comparative Example, not an Exampleof the Instant Claimed Test Method.

FIG. 10 is a DMA plot of a Flat Film Drawdown of Secondary PMoct,Supercoatings Candidate, this is a Comparative Example, not an Exampleof the Instant Claimed Test Method.

FIG. 11 is a DMA plot of a Tube of Secondary PMoct, SupercoatingsCandidate over Primary PMoct Supercoatings as put on wire using the DrawTower Simulator; this is a Comparative Example, not an Example of theInstant Claimed Test Method.

FIG. 12 is a Dynamic Mechanical Analysis (“DMA”) plot of composite filmof PMoct Primary (Example 1PB3) covered by PMoct Secondary (Example2SB3) applied Wet-on-Wet (abbreviated W-O-W).

FIG. 13 is a DMA plot of composite film of PMoct Primary (Example 1PB3)covered by PMoct Secondary (Example 2SB3) applied Wet on Dry(abbreviated W-O-D).

DETAILED DESCRIPTION OF THE INVENTION

The first aspect of the instant claimed invention is a method offormulating radiation curable Supercoatings for application to anoptical fiber used in a telecommunications network, wherein saidSupercoatings comprise at least two layers, the first layer being aprimary coating that is in contact with the outer layer surface of theoptical fiber and the second layer being a secondary coating in contactwith the outer surface of the primary coating, wherein the cured primarycoating on the optical fiber has the following properties after initialcure and after at least one month aging at 85° C. and 85% relativehumidity:

-   -   1) a % RAU of from about 84% to about 99%;    -   2) an in-situ modulus of between about 0.15 MPa and about 0.60        MPa; and    -   3) a Tube T_(g), of from about −25° C. to about −55° C.;    -   and wherein the cured secondary coating on the optical fiber has        the following properties after initial cure and after at least        one month aging at 85° C. and 85% relative humidity:    -   4) a % RAU of from about 80% to about 98%;    -   5) an in-situ modulus of between about 0.060 GPa and about 1.90        GPa; and    -   6) a Tube T_(g) of from about 50° C. to about 80° C.;    -   said method comprising the steps of:    -   a) determining the Maximum Acceptable Increase in Attenuation        requirements for the telecommunications network where the        optical fiber will be installed;    -   b) determining a Field Application Environment of the        Supercoatings comprising:    -   i) selecting the type of glass being used in the optical fiber;    -   ii) deciding whether the secondary coating of the Supercoatings        will be applied over the primary coating of the Supercoatings        wet-on-dry or wet-on-wet;    -   iii) selecting the type, number of lights and positioning of        lights along a draw tower manufacturing line that are used to        cure the Supercoatings on the optical fiber; and    -   iv) selecting the line speed at which the Supercoatings will be        applied;        -   c) formulating a primary coating composition in a liquid,            uncured state;        -   d) formulating a secondary coating composition in a liquid,            uncured state;    -   e) using a Three-Dimensional Laced Methodology, as shown in        FIGS. 2, 3 and 4, of    -   i) testing the primary coating and secondary coating of the        Supercoatings to determine if the Supercoatings parameters 1)        through 6) are achieved; wherein        -   if each and every one of the Supercoatings parameters 1)            through 6) are achieved then proceed to step f); and        -   if each and every one of the Supercoatings parameters 1)            through 6) have not been achieved, reformulate either or            both of the primary coating or secondary coating of the            Supercoatings and repeat step ii) until each and every one            of the Supercoatings parameters 1) through 6) are achieved;            and then    -   ii) verifying the integrity of the reformulation of the primary        coating and the secondary coating of the Supercoatings by        evaluating changes in each formulation relative to the other        formulation and relative to all of the Supercoatings        parameters 1) through 6);    -   f) using the results from step e)i) and step e)ii) to finalize        the selection of Supercoatings to achieve the Maximum Acceptable        Increase in Attenuation of the coated optical fiber.

The first step in the process is determining the Maximum AcceptableIncrease in Attenuation requirements for the telecommunications networkwhere the optical fiber will be installed. Determining the attenuationrequirements for the telecommunications network involves the designcriteria for the Optical Fiber Network. Some considerations in thedesign include: an understanding of how much of the network is straightline installation of multi-mode optical fiber as compared to how much ofthe network is Fiber-to-the-Home (abbreviated FFTH) installation ofsingle mode optical fiber. There are many other design criteria for anOptical Fiber network that are known to people of ordinary skill in theart of designing Optical Fiber Networks.

Specific Considerations in design of Optical Fiber Networks include thefollowing

It is currently known, that in contrast to traditional straight lineoptical fiber long haul networks, that FTTH applications have to work atleast at three wavelengths:

-   -   1310 nm (data/voice upstream)    -   1490 nm (data/voice downstream)    -   1550 nm (video signal).        Traditional optical fiber networks used Standard single mode        wavelengths of between 1310 nm and 1550 nm, with the wavelength        of 1625 nm being available for testing of the system. Now, with        the increasing demand for signal transmission it is anticipated        that future optical fiber networks will have to be able to        transmit signal containing actual data at 1310 nm, 1550 nm and        1625 nm. Optical fiber networks incorporating fiber that can        transmit at all three of these wavelengths are known to be more        vulnerable to both Macrobending and Microbending. Microbending        is known to be more damaging to transmission at a 1625        wavelength.

There are several sources for the standards for attenuation in thetelecommunications industry. One such standards setting organization isThe Telecommunications Industry Association (TIA), which is the leadingtrade association representing the global information and communicationstechnology (ICT) industries through such activities such as: Standardsdevelopment, Providing Market Intelligence, Government affairs guidance,Certification of optical fiber and networks containing optical fiber andadvice regarding World-wide environmental regulatory compliance. TIA'sUnited States Technical Advisory Groups (USTAG) also participates ininternational standards-setting activities, such as the InternationalElectrotechnical Commission (IEC).

Another source for the standards for attenuation in thetelecommunications industry is the IEC. The InternationalElectrotechnical Commission (IEC) is the leading global organizationthat prepares and publishes international standards for all electrical,electronic and related technologies. These serve as a basis for nationalstandardization and as references when drafting international tendersand contracts.

Telcordia is a U.S. based corporation that provides fiber optic media &components analysis & consulting services. They also write and keep alibrary of Generic Requirements for Optical Fiber.

All of these organizations have publicly available literature, reportsand standards that are used by people of ordinary skill in the art ofdesigning optical fiber networks.

Methods used to test for microbending sensitivity are described in IECTR 62221, First Edition 10-2001. There are currently four test methodsused to determine microbending sensitivity, which is reported inattenuation units of dB/km.

Method A—Expandable Drum calls for at least 400 m of fiber to be woundwith minimal tension around an expandable drum with material of fixedroughness on the drum surface. Method B—Fixed-Diameter Drum calls for atleast 400 m of fiber to be wound with 3N tension around a fixed-diameterdrum with material of fixed roughness on the drum surface. Method C—WireMesh calls for application of wire mesh (under load) to the fiber underTest. Method D—Basketweave calls for 2.5 km of fiber to be applied to afixed diameter drum via a “basketweave” wrap.

Of these four test methods, only Method D, specifically describes aprocedure to measure the microbending sensitivity of fibers as afunction of temperature and provides the microbending sensitivity over awide temperature range and suggests that temperature cycling couldinclude lower temperatures such as −60° C.

Throughout this patent application, microbending sensitivity using testMethod D—Basketweave will be spoken of in terms of a dB/Km number, at aspecified wavelength and temperature.

There are at least four different types of tests currently in use totest for Microbending Sensitivity with test results being reported inattenuation units of dB/km. Four specific Microbending Sensitivity testMethods are described in IEC TR 62221, First Edition 10-2001.

They are as follows:

-   -   Method A Expandable Drum: Calls for at least 400 m of fiber to        be wound with minimal tension around an expandable drum with        material of fixed roughness on the drum surface.    -   Method B Fixed-diameter drum: Calls for at least 400 m of fiber        to be wound with 3N tension around a fixed-diameter drum with        material of fixed roughness on the drum surface.    -   Method C Wire Mesh: Calls for application of wire mesh (under        load) to the fiber under Test.    -   Method D Basketweave: Calls for 2.5 km of fiber to be applied to        a fixed diameter drum via a “basketweave” wrap.

Throughout this patent application, Method D measured MicrobendingSensitivity will be discussed and reported in units of attenuation whichwill be spoken of in terms of a dB/Km number, at a specified wavelengthand temperature. It is understood that whatever Microbending Sensitivityis given, that the number given is the Maximum Acceptable Increase inAttemuation permissible for that optical fiber in a giventelecommunications network.

Of these four test methods, only Method D, specifically describes aprocedure to measure the Microbending Sensitivity of fibers as afunction of temperature and provides the Microbending Sensitivity over awide temperature range and suggests that temperature cycling couldinclude lower temperatures such as −60° C.

It is understood, within the industry, that it is unlikely that OpticalFibers in a telecommunications network would be routinely exposed totemperatures as low as −60° C. However, after recent field failures inChina, it is also beginning to be understood that having a specificationfor Microbending Sensitivity for the optical fiber in atelecommunications network at room temperature of approximately 25° C.is not sufficient to protect a telecommunications network from having“dark fiber” develop over the course of a winter where the temperatureis below freezing (0° C. or 32° F.) for extended periods of time.

Applicants have chosen to report Microbending Sensitivity as a change inattenuation from a baseline per the IEC procedure; this procedurerequires the reporting of change in attenuation be reported at specificwavelengths and a temperature of −60° C. Applicants believe thatreporting Microbending Sensitivity data at these extreme temperatureconditions will provide a type of “worst case scenario” possibility forMicrobending Sensitivity of the coated optical fiber in the field.

It is Applicants' position that if the Microbending Sensitivityproperties of the Optical Fiber at the −60° C. level are deemed to beacceptable, then it is reasonable to assume that the performance of theOptical Fiber at room temperature, assuming the same level of mechanicalstress, will also be acceptable.

Further to this point, at room temperature Microbending Sensitivitytesting it may or may not be possible to identify the difference inMicrobending Sensitivity between an Optical Fiber coated with astandard, “non-Supercoatings” coating, because neither Supercoatings ora non-Supercoatings is anywhere near their glass transition temperature(Tg) for the primary coating layer at room temperature.

The difference between an Optical Fiber coated with a standard“non-Supercoatings” coating and an Optical Fiber coated withSupercoatings shows up with Microbending Sensitivity testing at theextreme low temperatures because the standard “non-Supercoatings”Primary Layer exceeds its glass transition temperature at the extremelow temperatures and thus transitions from rubbery state to glassystate. Having the Primary Layer of an Optical Fiber coating being in theglassy state is known to cause an increase in Microbending Sensitivity.In contrast, the Tg of a Supercoatings Primary Layer is much lower andtherefore the Primary Layer of Supercoatings remains in the rubberyphase which is better for Microbending Sensitivity.

Another way of explaining the difference between standard “non-Radiationcurable Supercoatings” for Optical Fiber and Radiation curableSupercoatings for Optical Fiber is that the combination of fully cured,low modulus and low Tg coatings in the Primary Coating Layer and fullycured, high modulus, high Tg coatings in the Secondary Coating Layer ofthe Supercoatings leads to acceptable performance under the stress ofeither extreme temperature or mechanical stress or both temperature andmechanical stress with acceptable performance being gauged by the lowlevel of Microbending Sensitivity which is reflected in the fiber havingan acceptable increase in reported attenuation.

In current practice, it is understood that the Telecommunicationsnetwork generally requests that Optical Fiber be supplied with a knownmaximum attenuation at 1310 nm and room temperature. This highesttolerable level of attenuation is known to people of ordinary skill inthe art of design criteria for Telecommunications networks.

For Optical Fibers coated with Radiation curable Supercoatings, it ispossible and desirable to report Microbending Sensitivity at threeseparate wavelengths and at a very cold (−60° C.) temperature. This datacan then be used by the Network designer to understand the limits, andbe able to predict failure modes for the network. It is applicants'position that a network containing Optical Fibers coated with standard,“non-Supercoatings” will have much less tolerance to the stress involvedfrom the cable environment of temperature extremes and mechanical forcesthan will a network containing Optical Fibers coated with Radiationcurable Supercoatings. Another factor is that it is believed that usingRadiation curable Supercoatings to coat Optical Fiber will provide aTelecommunications network with sufficient data to be able to designwithout requiring the same “safety margin” as is built in with usingstandard “non-Radiation curable Supercoatings” to coat Optical Fiber.

The next step in the process is determining the Field ApplicationEnvironment of the Supercoatings requirements for the telecommunicationsnetwork where the optical fiber will be installed. The Field ApplicationEnvironment involves the understanding of four factors:

-   -   i) the type of glass being used in the optical fiber;    -   ii) whether the Supercoatings Secondary Layer will be applied        over the Supercoatings Primary Layer wet on dry or wet on wet;    -   iii) the type, number of lights and positioning of lights along        the draw tower manufacturing line that are used to cure the        Supercoatings on the optical fiber; and    -   iv) the line speed at which the Supercoatings will be applied.

Regarding element i): Optical Fiber is known to have standard grades forinstallation of long haul straight cable. Recently various grades of“bend resistant” Optical Fiber have been developed by Optical FiberSuppliers such as Corning and Drake and OFS and YOFC and others. Thesebend resistant Optical Fibers are being deployed in Fiber to the Node(FTTX) and Fiber to the Home (FTTH) applications.

Details about standard grade and Microbend resistant Optical Fibers areavailable from the Suppliers own literature and websites.

Current commercial Optical Fiber available for sale include: Corning®InfiniCor® optical fibers, Corning® ClearCurve® OM2/OM3/OM4 multimodeoptical fiber, Corning® ClearCurve® single-mode optical fiber, Corning®SMF-28e® XB optical fiber, Corning® SMF-28® ULL optical fiber, Corning®LEAF® optical fiber, Corning® Vascade® optical fibers and CorningSpecialty Fiber, Draka BendBright SingleMode (BB), Draka TeraLightSinglemode (TM), Draka TeraLight Ultra Singlemode (TU), DrakaBendBright-XS (BX), Draka Enhanced Single Mode, Draka NZDSF-LASinglemode (LA), OFS AllWave® Zero Water Peak (ZWP) and newly introducedOFS AllWave FLEXZWP Fibers, OFS LaserWave® Fibers, OFS Access ADVANTAGE™System. OFS HCS®, OFS FiberWire®, and OFS PYROCOAT® brand technologies,YOFC HiBand GIMM fiber, YOFC High Temperature Fibre (HTF) Series, YOFCHiBand Graded-index Multimode Optical Fiber (50/125 & 62.5/125 um) andothers.

Typically fiber to be deployed in straight line applications undergoesless stress, and less microbending than fiber to be deployed in FTTX andFTTH applications. Therefore, the selection of Radiation curableSupercoatings to be applied to fiber for FTTX and FTTH applications iscrucial to the performance of FTTX and FTTH optical fiber. Accordingly,whenever the optical fiber to be coated is designated for FTTX and FTTHapplications, the Supercoatings must be highly resistant tomicrobending.

Unique to formulating Supercoatings is just how much of the formulationrequirements to achieve the six required properties are dependent uponthe Mechanical aspects of the coating of an optical fiber. For example,it is possible to coat a standard grade of Optical Fiber withSupercoatings and obtain a Coated Optical Fiber with desired attenuationproperties, but it is also possible to coat a “Bend-Resistant” premiumgrade of Optical Fiber with a standard, “non. Supercoatings”, and havethe result be a coated optical fiber with unacceptable MicrobendingSensitivity leading to the failure in achieving the system requiredtolerable level of attenuation. Therefore, in order to produce anoptical fiber with the desired attenuation properties it is desirable,optionally even necessary, for the formulator of Supercoatings to havean understanding of the details of the optical fiber production process.These details include the type of glass, the processing temperature, theatmosphere surrounding the application of coating(s), the line speed,the type of radiation source, typically described as a “curing lamp”,and the location and number of curing lamps along the processing lineand whether the secondary coating is applied over the primary coatingwet on wet or wet on dry. These types of mechanical aspects to the glassprocessing have, in the past, not been of interest to the formulator ofthe Optical Fiber coatings because the formulator focused on the OpticalFiber coatings and the glass manufacturer focused on the glass. Asstated previously, without an adequate amount of information about theprocessing of the glass, it is possible to coat a standard grade ofOptical Fiber with Supercoatings and obtain a Coated Optical Fiber withdesired Microbending Sensitivity properties, but it is also possible tocoat a “Bend-Resistant” premium grade of Optical Fiber with a standard,non-Supercoatings, and have the result be a coated optical fiber withoutthe desired Microbending Sensitivity properties.

Regarding element iii) the type, number of lights and positioning oflights along the draw tower manufacturing line that are used to cure theSupercoatings on the optical fiber; the use of conventional ultravioletmercury arc lamps to emit ultraviolet light suitable to cure radiationcurable coatings applied to optical fiber is well known. Ultraviolet arclamps emit light by using an electric arc to excite mercury that residesinside an inert gas (e.g., Argon) environment to generate ultravioletlight which effectuates curing. Alternatively, microwave energy can alsobe used to excite mercury lamps in an inert gas medium to generate theultraviolet light. Throughout this patent application, arc excited andmicrowave excited mercury lamp, plus various additives (ferrous metal,Gallium, etc.) modified forms of these mercury lamps are identified asmercury lamps. Conventional ultraviolet mercury arc lamps are the“state-of-the-art” when it comes to curing of radiation curable coatingsfor optical fiber.

However, the use of ultraviolet mercury lamps as a radiation sourcesuffers from several disadvantages including environmental concerns frommercury and the generation of ozone as a by-product. Further, mercurylamps typically have lower energy conversion ratio, require warm-uptime, generate heat during operation, and consume a large amount ofenergy when compared with Lights that are generated by Light EmittingDiodes “LED”.

Knowing what type of light is going to be used in the curing of theRadiation Curable Supercoatings is critical information because in theproduction of coated optical fiber, the heat generated by the UV mercurylamps can negatively impact the liquid coating in that if the coating isnot formulated to avoid the presence of volatiles, those volatiles maybe excited and deposit upon the quartz tube surface, blocking the UVrays from irradiating the liquid coating on the glass fiber whichinhibits the curing of the liquid coating to a solid.

In contrast to ultraviolet mercury lamps, light emitting diodes (LEDs)are semiconductor devices which use the phenomenon ofelectroluminescence to generate light. LEDs consist of a semiconductingmaterial doped with impurities to create a p-n junction capable ofemitting light as positive holes join with negative electrons whenvoltage is applied. The wavelength of emitted light is determined by thematerials used in the active region of the semiconductor. Typicalmaterials used in semiconductors of LEDs include, for example, elementsfrom Groups 13 (III) and 15 (V) of the periodic table. Thesesemiconductors are referred to as III-V semiconductors and include, forexample, GaAs, GaP, GaAsP, AlGaAs, InGaAsP, AlGaInP, and InGaNsemiconductors. Other examples of semiconductors used in LEDs includecompounds from Group 14 (IV-IV semiconductor) and Group 12-16 (II-VI).The choice of materials is based on multiple factors including desiredwavelength of emission, performance parameters, and cost.

Early LEDs used gallium arsenide (GaAs) to emit infrared (IR) radiationand low intensity red light. Advances in materials science have led tothe development of LEDs capable of emitting light with higher intensityand shorter wavelengths, including other colors of visible light and UVlight. It is possible to create LEDs that emit light anywhere from a lowof about 100 nm to a high of about 900 nm. Currently, known LED UV lightsources emit light at wavelengths between about 300 and about 475 nm,with 365 nm, 390 nm and 395 nm being common peak spectral outputs. Seetextbook, “Light-Emitting Diodes” by E. Fred Schubert, 2^(nd) Edition, ©E. Fred Schubert 2006, published by Cambridge University Press.

LED lamps offer advantages over conventional mercury lamps in curingapplications. For example, LED lamps do not use mercury to generate UVlight and are typically less bulky than mercury UV are lamps. Inaddition, LED lamps are instant on/off sources requiring no warm-uptime, which contributes to LED lamps' low energy consumption. LED lampsalso generate much less heat, with higher energy conversion efficiency,have longer lamp lifetimes, and are essentially monochromatic emitting adesired wavelength of light which is governed by the choice ofsemiconductor materials employed in the LED.

Several manufacturers offer LED lamps for commercial curingapplications. For example, Phoseon Technology, Summit UV Honle UVAmerica, Inc., IST Metz GmbH, Jenton International Ltd., LumiosSolutions Ltd., Solid UV Inc., Seoul Optodevice Co., Ltd, SpectronicsCorporation, Luminus Devices Inc., and Clearstone Technologies, are someof the manufacturers currently offering LED lamps for curing ink-jetprinting compositions, PVC floor coating compositions, metal coatingcompositions, plastic coating composition, and adhesive compositions.

Regarding element iv) the line speed at which the Supercoatings will beapplied, in D1381 RADIATION CURABLE SUPERCOATINGS FOR OPTICAL FIBER,U.S. patent application Ser. No. 11/955,541, filed Dec. 13, 2007,published on Sep. 18, 2009 as US Published Patent Application20080226909, entitled it is stated that a Supercoating may be applied tosingle-mode optical fiber at a line speed of between about 750meters/minute to about 2100 meters/minute. As of the date of filing thispatent application, Oct. 8, 2010, the optical fiber industry has nowprogressed to the point where it is possible to draw single-mode opticalfiber at line speeds in excess of 2100 meters/minute. It is alsopossible to draw single-mode optical fiber at line speeds in excess of2200 meters/minute. It is also possible to draw single-mode opticalfiber at line speeds in excess of 2300 meters/minute. It is believed,without intending to be bound thereby that it may also be possible todraw single-mode optical fiber at line speeds in excess of 2350meters/minute. It is believed, without intending to be bound thereby,that it may also be not possible to draw single-mode optical fiber atline speeds in excess of 2400 meters/minute.

The next step in the process involves using a Three-Dimensional LacedMethodology Evaluation of candidate Radiation curable Supercoatings byevaluation of the Radiation curable Supercoatings Primary Layer andSecondary Layer. Historically Primary and Secondary coatings for opticalfiber were formulated and reformulated according to a two-dimensionaldiagramed way of formulating. FIG. 1 is a diagram of historicaldepiction of formulation diagram for how typical formulating for opticalfiber coatings has been done-illustrating the prior art.

In FIG. 1, Decision Chart 10 shows the two-dimensional Prior Artapproach to formulating optical fiber coatings. In FIG. 1, desirablefunctional property A is illustrated by circle A, Review Point Brepresents the test to determine whether the liquid optical fibercoating or the cured coating, either in the form of a flat film or inthe form of a tubular coating on the optical fiber, has the desiredfunctional property. If the optical fiber coating does have the desiredfunctional property than the decision tree goes to yes and the inquiryis over. If the optical Fiber coating does not have the desiredfunctional property, the formulator reviews the formulation anddetermines the change to make, as represented by parallelogram D, andthen in rectangle C, the formulation is changed. The functional propertyis retested at Review Point B, and if the desired functional property isobtained then the inquiry is over. If the desired functional property isnot obtained, then the decision tree goes back to the top and otherreformulating options by the formulator are considered until the nextpossible formulation is determined and then the formulation is changedand then the desired functional property is retested. This continuesuntil the desired physical property is obtained.

The possible ways to change the coating are illustrated by theinformation contained n Table 1A, 1B, 1C, 1D, 1E, 2A, 2B, 2C, 2D, 2E,1F, 2F, 1G, 2G, 1H, 2H, 1J, and 2J which summarize the state-of-the-artunderstanding of the ingredients that may or may not be used informulating Primary and Secondary Radiation Curable Coatings for opticalfiber with respect to creating formulations with physical properties ofthe Primary Coating Layers and Secondary Coating Layers on the OpticalFiber that meet the rigorous criteria of Supercoatings. In addition tothe information in the Tables contained herein, additional informationmay be found in issued patents, published patent applications,scientific papers and other information commonly known to people ofordinary skill in the art of Radiation Curable Coatings for OpticalFiber.

TABLE 1A Choice of Oligomer for Supercoatings-PrimaryDisadvantages-includes Chemistry of Oligomer Sub-Chemistry, within theundesirable interactions for Supercoatings-Primary category Benefitswith other components 1. urethane (meth)acrylate other UV-curableend-groups fast cure, toughness, stability, high viscosity (mostcommonly used e.g. vinyl ether, versatility, many polyols available,oligomer for optical fiber (meth)acrylamide, vinyl amide ease ofmanufacture coatings) 2. polyester (meth)acrylate other UV-curableend-groups fast cure, low viscosity, versatility, low elongation, poorere.g. vinyl ether, many polyols and acids available, hydrolyticstability, (meth)acrylamide, vinyl amide oxidative stability moredifficult to manufacture 3. silicone (meth)acrylate other UV-curableend-groups very low Tg, hydrophobic and expensive, specialized e.g.vinyl ether, lipophobic, fast cure, stability, low manufacture,refractive (meth)acrylamide, vinyl amide viscosity index may be too low4. hydrocarbon (e.g. other UV-curable end-groups very low Tg,hydrophobic, hydrolytic poorer oxidative polybutadiene) e.g. vinylether, stability, low viscosity stability, poorer (meth)acrylate(meth)acrylamide, vinyl amide solubility, lipophilic 5. fluorocarbonother UV-curable end-groups low Tg, hydrophobic and lipophobic,expensive, poorer (meth)acrylate e.g. vinyl ether, fast cure, stability,low viscosity solubility, refractive (meth)acrylamide, vinyl amide indexmay be too low, specialized manufacture 6. thiol-ene various enesincluding, strong network structure, low odor, shelf stabilitynorbornene, vinyl ether, vinyl viscosity, good cured stability ester,vinyl amide, allyl ether, allyl ester, allyl amide, styrene, alkenes(aliphatic enes are used for low Tg) Disadvantages-includesSub-Chemistry, within the undesirable interactions Chemistry of Oligomercategory Benefits with other components 7. acrylated acrylic polymerOther UV-curable end-groups or copolymer e.g. vinyl ether, (meth)acrylamide, vinyl amide 8. cationic epoxy various cationically curablelow shrinkage, good adhesion, low slower cure speed, post groupsincluding glycidyl viscosity, stability curing effect, lower ether,glycidyl ester, vinyl elongation ether, oxetane, hydroxyl (aliphaticmaterials are used for low Tg)

TABLE 1B Choice of Oligomer for Supercoatings-Primary Selection ofPolyol to Disadvantages-includes formulate Urethane Sub-Chemistry,within the undesirable interactions Oligomer category Benefits withother components 1. polyether (most poly(alkylene glycols), hydrolyticstability, flexibility, low oxidative stability commonly used polyol forpoly(arylene glycols), viscosity optical fiber oligomers) copolymerswith other types of polyols 2. polyester aliphatic, aromatic, linear,oxidative stability higher Tg, poorer branched oxidative stability 3.polycarbonate aliphatic, aromatic, linear, oxidative and hydrolyticstability higher Tg, potential branched crystallinity 4. hydrocarbonaliphatic, aromatic, linear, hydrophobic, good stability poor oxidativestability branched, cyclic, saturated, if unsaturated, unsaturatedsolubility, lipophilic 5. silicone aliphatic, aromatic, linear,hydrophobic and lipophobic, expensive, refractive branched stability,low viscosity index may be too low 6. fluorocarbon aliphatic, aromatic,linear, hydrophobic and lipophobic, expensive, refractive branchedstability, low viscosity index may be too low 7. bio-based Variousvegetable, see, nut, Generally low Tg, hydrophobic, good May have lowerpurity biomass and other plant- stability, sustainable or homogeneityderived polyols

TABLE 1C Choice of Oligomer for Supercoatings-Primary Selection ofIsocyanate to Disadvantages-includes formulate Urethane Sub-Chemistry,within the undesirable interactions Oligomer category** Benefits withother components 1. aromatic TDI, MDI faster reaction, low costyellowing, toxicity 2. aliphatic IPDI, HDI, TMDI low yellowing highercost, slower reaction 3. alkyl-aryl TMXDI stability higher cost, slowerreaction 4. DESMODUR ® W* bis(4- Polyurethane resins based onnon-homogenous isomer isocyanotocyclohexyl) *Desmodur ® W diisocyanatehave blending may lead to methane a high degree of flexibility coupledreproducibility issues for also known as PICM, with good mechanicalstrength. each oligomer made with hydrogenated MDI (HMDI They areresistant to abrasion and this isocyanate. The or H12MDI), saturatedhydrolysis and retain gloss and reproducibility issues for MDI (SMDI),reduced MDI physical properties upon each oligomer may then (RMDI), andweathering. A unique feature of lead to unexpected dicyclohexylmethane*Desmodur ® W diisocyanate is its performance properties of diisocyanateability to form optically clear formulated coating polyurethanes whencombined with suitable polyol coreactants. *trademark of Bayer**definitions for abbreviations are as follows: TDI is toluenediisocyanate MDI is methylenebis(phenyl isocyanate) OR MethylDi-P-Phenylene Isocyanate IPDI is isophorone diisocyanate HDI isHexamethylene diisocyanate TMDI is Trimethyl hexamethylene diisocyanateTMXDI is TMXDI ® (Meta) Aliphatic Isocyanate, available from CytecIndustries Inc.

TABLE 1D Choice of Oligomer for Supercoatings-PrimaryDisadvantages-includes Selection of Inhibitor to Sub-Chemistry, withinthe undesirable interactions formulate oligomer category Benefits withother components 1. Hydroquinone type Hydroquinone, Methylether Improveprocess and shelf stability Color change; retard hydroquinone, Butylpolymerization reaction hydroxytoluene. 2. Butylated hydroxyl PhenolicLow Cost, good solubility, Less effective at higher toluene (most widelyused) effective temperatures 3. Phenothiazine Improve Process and shelfstability Color change; retard polymerization reaction

TABLE 1E Choice of Oligomer for Supercoatings-PrimaryDisadvantages-includes Selection of Catalyst to Sub-Chemistry, withinthe undesirable interactions formulate oligomer category Benefits withother components 1. Amine compounds Tertiary amines Versatile catalystSide reactions lead to byproducts, such as urea, isocyanate trimers. 2.Organometallic Mercury, lead, tin, bismuth, Highly effective Some arehighly toxic and complexes zinc compounds hazardous

TABLE 2A Choice of Oligomer for Supercoatings-SecondaryDisadvantages-includes Sub-Chemistry, within the undesirableinteractions Chemistry of Oligomer category Benefits with othercomponents 1. urethane (meth)acrylate other UV-curable end-groups fastcure, toughness, stability, high viscosity e.g. vinyl ether,versatility, many polyols available, (meth)acrylamide, vinyl amide easeof manufacture (most commonly used oligomer chemistry for optical fibercoatings) 2. polyester (meth)acrylate other UV-curable end-groups fastcure, low viscosity, versatility, low elongation, poorer e.g. vinylether, many polyols and acids available, hydrolytic stability, more(meth)acrylamide, vinyl amide oxidative stability difficult tomanufacture 3. silicone (meth)acrylate other UV-curable end-groupshydrophobic and lipophobic, fast generally low Tg, e.g. vinyl ether,cure, stability, low viscosity expensive, specialized (meth)acrylamide,vinyl amide manufacture, refractive (diphenyl silicone acrylates indexmay be too low have high Tg) 4. hydrocarbon other UV-curable end-groupshydrophobic, hydrolytic stability, poorer oxidative stability,(meth)acrylate e.g. vinyl ether, low viscosity poorer solubility,(meth)acrylamide, vinyl amide lipophilic, generally low (aromatic andcyclic Tg hydrocarbons can have high Tg) 5. fluorocarbon otherUV-curable end-groups hydrophobic and lipophobic, fast expensive, poorer(meth)acrylate e.g. vinyl ether, cure, stability, low viscositysolubility, refractive index (meth)acrylamide, vinyl amide may be toolow, (aromatic and cyclic specialized manufacture, fluorocarbons canhave high generally low Tg Tg) 6. acrylated acrylic polymer OtherUV-curable end-groups Adjustable Tg, good stability, Specializedmanufacture, or copolymer e.g. vinyl ether, good chemical resistancegenerally high viscosity (meth)acrylamide, vinyl amide 7. thiol-enevarious enes including, strong network structure, low odor, shelfstability norbornene, vinyl ether, vinyl viscosity, good cured stabilityester, vinyl amide, allyl ether, allyl ester, allyl amide, styrene,alkenes (aromatic or cyclic enes for higher Tg) 8. cationic epoxyvarious cationically curable low shrinkage, good adhesion, slower curespeed, post groups including glycidyl low viscosity, stability curingeffect, lower ether, glycidyl ester, vinyl elongation ether, oxetane,hydroxyl (aromatic materials for higher Tg)

TABLE 2B Choice of Oligomer for Supercoatings-Secondary Chemistry ofpolyol to Disadvantages-includes formulate Urethane Sub-Chemistry,within the undesirable interactions with oligomer category Benefitsother components 1. polyether (most poly(alkylene glycols), hydrolyticstability, flexibility, oxidative stability, generally commonly usedpolyol for poly(arylene glycols), cure speed, low viscosity low Tgoptical fiber oligomers) copolymers with other types of polyols 2.polyester aliphatic, aromatic, linear, oxidative stability, higher Tgpoorer oxidative stability branched 3. polycarbonate aliphatic,aromatic, linear, oxidative and hydrolytic stability, potentialcrystallinity branched higher Tg 4. hydrocarbon aliphatic, aromatic,linear, hydrophobic, good stability poor oxidative stability ifbranched, cyclic, saturated, unsaturated, solubility, unsaturated(aromatic and lipophilic cyclic hydrocarbons can have high Tg) 5.silicone aliphatic, aromatic, linear, hydrophobic and lipophobic,expensive, refractive index branched (diphenyl silicone stability, lowviscosity may be too low, generally low acrylates have high Tg) Tg 6.bio-based Various vegetable, seed, nut, Generally low Tg, hydrophobic,May have lower purity or biomass and other plant- good stability,sustainable homogeneity derived polyols

TABLE 2C Choice of Oligomer for Supercoatings-Secondary Chemistry ofIsocyanate to Disadvantages-includes formulate Urethane Sub-Chemistry,within the undesirable interactions with other oligomer categoryBenefits components 1. aromatic TDI, MDI faster reaction, low costyellowing, toxicity 2. aliphatic IPDI, HDI, TMDI low yellowing highercost, slower reaction 3. alkyl-aryl TMXDI stability higher cost, slowerreaction

TABLE 2D Choice of Oligomer for Supercoatings-Secondary Chemistry ofInhibitor to Sub-Chemistry, within the Disadvantages-includesundesirable formulate oligomer category Benefits interactions with othercomponents 1. Hydroquinone type Hydroquinone, Methylether Improveprocess and shelf Color change; retard polymerization hydroquinone,Butyl stability reaction hydroxytoluene. 2. Butylated hydroxyl PhenolicLow Cost, good Less effective at higher temperatures toluene (mostwidely used) solubility, effective 3. phenothiazine Improve process andshelf Color change, retard polymerization stability reaction

TABLE 2E Choice of Oligomer for Supercoatings-Secondary Chemistry ofCatalyst to Sub-Chemistry, within the Disadvantages-includes undesirableformulate urethane oligomer category Benefits interactions with othercomponents 1. Amine Compounds Tertiary amines Versatile catalyst Sidereactions lead to byproducts, such as urea, isocyanate trimers. 2.Organometallic Mercury, lead, tin, bismuth, Highly effective Some arehighly toxic and hazardous complexes zinc compounds

TABLE 1F Choice of Photoinitiator for Supercoatings-PrimaryDisadvantages-includes undesirable interactions Chemistry Benefits withother components 1. α-hydroxy ketones fast cure, low yellowing, lowcost, good can be volatile through-cure and surface cure 2. (bis)acylphosphine oxides very fast cure, low yellowing, good more expensive,may have crystals through-cure 3. benzophenones low cost, goodsurface-cure require an amine, slower, yellows 4. polymericphotoinitiators low volatility, good through-cure and more expensivesurface-cure 5. others (many) may have low cost generally slower-curing,may have lower shelf- stability, may yellow

TABLE 2F Choice of Photoinitiator for Supercoatings-SecondaryDisadvantages-includes undesirable interactions Chemistry Benefits withother components 1. α-hydroxy ketones fast cure, low yellowing, lowcost, good can be volatile through-cure and surface cure 2. (bis)acylphosphine oxides very fast cure, low yellowing, good more expensive,may have crystals, poorer through-cure, good for colored secondariessurface-cure 3. benzophenones low cost, good surface-cure require anamine, slower, yellows 4. polymeric photoinitiators low volatility, goodthrough-cure and more expensive surface-cure 5. morpholino-containinggood for colored secondaries may screen too much UV light from reachingprimary coating in wet-on-wet process 6. others (many) may have low costgenerally slower-curing, may have lower shelf- stability, may yellow

TABLE 1G Choice of Adhesion Promoter for Supercoatings-PrimaryDisadvantages-includes undesirable interactions Chemistry Benefits withother components 1. silane coupling agents good dry and wet adhesionmoisture-sensitive (shelf-stability issue), possible to cause reducedcure speed and lower modulus 2. acid-functional materials good dryadhesion generally poorer wet adhesion 3. polar monomers or oligomersgood dry adhesion generally poorer wet adhesion

TABLE 2G Choice of Adhesion Promoter for Supercoatings-SecondaryChemistry None, adhesion promoters are not used in Secondary Coatings,only in Primary Coatings

TABLE 1H Choice of Diluent Monomer for Supercoatings-PrimaryDisadvantages-includes undesirable interactions Chemistry Benefits withother components 1. alkyl (meth)acrylate generally low Tg, hydrophobic,good odor, slower cure speed, may be crystalline, stability, low cost,good diluent (generally volatile under high heat output of conventionalmonofunctional monomer used for lower mercury UV lights crosslinkdensity and modulus) 2. aryl or cyclic (meth)acrylate generally higherTg, hydrophobic may be volatile or crystalline 3. ether (meth)acrylategenerally low Tg, fast cure speed, generally more hydrophilic, pooreroxidative stability good diluent, aromatics have good dry adhesion(generally monofunctional monomer used for lower crosslink density andmodulus) 4. hydroxyl-functional, acid- good dry adhesion, fast curespeed generally higher Tg, more hydrophilic, can react functional, andother polar (generally monofunctional monomer used with other coatingcomponents monomers for lower crosslink density and modulus) 5.(meth)acrylamides and vinyl good dry adhesion, fast cure speed generallyhigher Tg, more hydrophilic amides (generally monofunctional monomerused for lower crosslink density and modulus)

TABLE 2H Choice of Diluent Monomer for Supercoatings-SecondaryDisadvantages-includes undesirable interactions Chemistry Benefits withother components 1. alkyl (meth)acrylate hydrophobic, goodstress-relaxation if volatility, odor, slower cure speed, may bebranched, good stability, low cost, good crystalline diluent (generallymultifunctional monomer used for higher crosslink density and modulus)2. aryl or cyclic (meth)acrylate generally higher Tg, hydrophobic Somearyl species, e.g. phenoxy ethyl (generally multifunctional monomer usedacrylate, are volatile under high heat output for higher crosslinkdensity and modulus) of conventional mercury UV lights or crystalline;therefore when an aryl reactive diluent monomer is present that has amolecular weight less than about 300, it should be present at no morethan about 10 wt. % of the total formulation 3. ether (meth)acrylategood stress-relaxation if branched, fast cure more hydrophilic, pooreroxidative stability speed, generally good diluent (generallymultifunctional monomer used for higher crosslink density and modulus)4. hydroxyl-functional, acid- fast cure speed more hydrophilic, canreact with other coating functional, and other polar (generallymultifunctional monomer used components monomers for higher crosslinkdensity and modulus) 5. (meth)acrylamides and vinyl fast cure speed morehydrophilic amides (generally multifunctional monomer used for highercrosslink density and modulus)

TABLE 1J Choice of Stabilizer for Supercoatings-PrimaryDisadvantages-includes undesirable interactions Chemistry Benefits withother components 1. hindered phenol good for oxidative stability, lowyellowing may have poor solubility, crystallinity, high cost 2. hinderedamine good for low yellowing basicity (may lower glass strength), mayreact with other coating components 3. UV absorbers good for lowyellowing may slow cure speed of both secondary and primary coating 4.others e.g. phosphites, may improve cured coating stability and may havepoor solubility, crystallinity, high cost sulfides, metallic, mixedreduce yellowing stabilizers . . .

TABLE 2J Choice of Antioxidant for Supercoatings-SecondaryDisadvantages-includes undesirable interactions Chemistry Benefits withother components 1. hindered phenol good for oxidative stability, lowyellowing may have poor solubility, crystallinity, high cost 2. hinderedamine good for low yellowing basicity (may lower glass strength), mayreact with other coating components 3. UV absorbers good for lowyellowing may slow cure speed of both secondary and primary coating 4.others e.g. phosphites, may improve cured coating stability and may havepoor solubility, crystallinity, high cost sulfides, metallic, mixedreduce yellowing stabilizers . . .

In contrast to the “two-dimensional” approach illustrated in FIG. 1,FIG. 2 illustrates step 2 is the first aspect of the instant claimedinvention method for formulating Supercoatings for Optical Fiber. FIG. 2shows six Decision Charts, 10, 20, 30, 40, 50 and 60 linked together ina three dimensional model by linking lace 307. Linking Lace 307illustrates that any formulation change made in either the PrimaryCoating Layer or the Secondary Coating Layer of an Optical FiberSupercoatings means that the other desired properties of an OpticalFiber Supercoatings must be tested after the initial change has beenmade, in order to be certain that one or more changes in the formulationdon't lead to a negative influence on one or more functional propertiesof the Primary Coating Layer and Secondary Coating Layer.

The six necessary properties for Supercoatings for Optical Fiber are asfollows:

The cured Primary Coating on the optical fiber has the followingproperties after initial cure and after one month aging at 85° C. and85% relative humidity:

A) a % RAU of from about 84% to about 99%;

B) an in-situ modulus of between about 0.15 MPa and about 0.60 MPa; and

C) a Tube Tg, of from about −25° C. to about −55° C.;

wherein the cured Secondary Coating on the optical fiber has thefollowing properties after initial cure and after one month aging at 85°C. and 85% relative humidity:

A) a % RAU of from about 80% to about 98%;

B) an in-situ modulus of between about 0.60 GPa and about 1.90 GPa; and

C) a Tube Tg, of from about 50° C. to about 80° C.

Step ii) of the instant claimed invention, as illustrated in FIG. 2,shows that any formulation change made to affect one of these sixproperties, means that all of the other five functional properties mustbe tested as well, to make sure that changing one aspect of theSupercoatings does not affect the other five aspects.

FIG. 3 shows the second embodiment of step ii) of the instant claimedmethod for formulating Supercoatings for Optical Fiber. In FIG. 3, thepossible changes involving reformulation of a Primary Coating Layer orSecondary Coating Layer of Supercoatings must be tested against eachother to see if one change to achieve a desired functional propertycould also cause other changes that would negate a desired functionalproperty.

FIG. 4 shows the third embodiment of step ii) of the instant claimedmethod for formulating Supercoatings for Optical Fiber. In FIG. 4, thepossible changes are linked by linking laces both horizontally andvertically amongst the six necessary functional Supercoatingsproperties. This linkage of properties is the essence of what makesSupercoatings for Optical Fibers different from simply a primary coatingcovered by a secondary coating layer. With Supercoatings for opticalfiber, the reality is that instead of formulating the Primary andSecondary coating layers separately from each other, that anyformulation change in one of the layers, must be tested against all theproperties required of the Supercoatings.

The second aspect of the instant claimed invention is the Method of thefirst aspect of the instant claimed invention, in which theThree-Dimensional Laced Methodology includes using a Multi-Layer FilmDrawdown method to evaluate composite fused Primary Coating Layer andSecondary Coating Layer of Radiation curable Supercoatings.

The third aspect of the instant claimed invention is a Multi-Layer FilmDrawdown Method comprising the steps of:

-   -   a) selecting a substrate for the test;    -   b) applying a Primary coating to the substrate using a defined        thickness drawdown bar;    -   c) optionally curing the Primary coating;    -   d) applying a Secondary coating to the Primary coating using a        defined thickness drawdown bar, wherein the defined thickness of        the drawdown bar to apply the Secondary coating is greater than        the defined thickness of the drawdown bar used to apply the        primary coating;    -   e) applying radiation to the multi-layer film sufficient to        effectuate the cure of both the Primary and Secondary into a        Fused Composite film;    -   f) removing the film from the substrate; and evaluating the        functional properties of the cured film.

FIG. 5 shows one such Film.

The Multi-Layer Film Drawdown method flat plate substrate method forevaluation of layers of potential Radiation curableSupercoatings-Primary and Secondary Layers comprises the followingsteps:

1) For reference the general method for preparing drawdown films for UVcuring is described by Szum et al., 43rd IWCS Proceedings (1994), p. 59.

2) The typical practice is to start with a clean single-thicknesswindow-pane glass. One or more small daubs of test coatings are appliedto the glass plate itself, or to an overlaid polyester sheet coveringthe glass plate, and drawn down with a Bird type calibrated bar tospread a coherent thin film of 25μ to 75μ. One such Bird type bar forthe first layer has a film deposit height of 1.5 mils. These testcoatings are most typically inner primary coatings.

3) Immediately after this first drawdown, a second drawdown is made overthe top and wide enough to cover the edges of the first drawdown films.This second drawdown is also made with a Bird type bar calibrated todeposit a film of typically 75μ to 254μ. One such Bird type bar for thesecond layer has a film deposit height of 3.0 mils. The glass plate withthe two drawdowns and the consequent composite films is exposed tosuitable actinic radiation to achieve the desired degree of cure. Thismethod is known as the wet-on-wet method.

4) A similar method known as wet-on-dry method, is conducted in the samemanner as the wet-on-wet method described above; except the firstdrawdown films are exposed to actinic radiation to effectuate the cureof the Primary Coating Layer. After this radiant exposure the seconddrawdown is made and the plate is then further exposed to radiation toeffectuate the cure of the Secondary Layer and the Primary Layer into aFused Composite film.

5) This procedure results in the glass plate having upon its surfacearea cured composite films composed of a first layer of specifiedthickness and a second layer of a thickness calculated by the differenceof the thickness of the first layer subtracted from the nominalthickness of the calibrated Bird type bar used for the secondovercoating drawdown. These Fused Composite films are then suitable fortypical testing related to the properties desirable in Radiation curableSupercoatings intended for optical fiber applications.

The method is used to apply some small dots of primary to a glass plateand drawdown with a 1 mil or 1.5 mil Bird Bar. While the primary isstill uncured, a second drawdown of a colored secondary coating layer ismade over the primary coating layer but with a 3 mil bar. The result isobserved to be acceptably uniform as can be seen in FIG. 5.

In practice, the Supercoatings Primary Layer is drawn down with a 1.5mil bar, then a candidate for Supercoatings Secondary layer, observed asa brown layer, Example 3SA3 Color twoH, (Color 2HBrown) is drawn downover the Supercoatings Primary with a 3 mil bar. After this wet-on-wetapplication, the plate is exposed to radiation sufficient to effectuatethe cure of both the Primary Coating Layer and the Secondary CoatingLayer into a Fused Composite Film.

In FIG. 5, The Fused Composite film appears to be very uniform with thedarker areas being 3 mil of colored secondary, and the lighter areas 1.5mil each of primary and colored secondary over the top. The FusedComposite film is easily removable and hand able for measurements ofthickness and % RAUs, a critical measurement for both layers ofSupercoatings for Optical Fiber.

Follow-up analysis shows very little mixing of the layers during thedual-drawdown method.

It was surprising to discover that a simple w-o-w drawdown would leaveboth the bottom and top layers intact with their separate identities,and yet the two layers then fuse into a Fused Composite film duringcure.

The lack of mixing of the layers is further illustrated in FIGS. 7, 8and 9.

FIG. 7 is Spectra “all”, which shows 4 spectra with a comparableappearance to two sets of two sitting on top of each other.

FIG. 8 is Spectra “Brown” showing the colored secondary portion only,and the top of the dual drawdown portion. The two spectra match up quitewell.

FIG. 9 is Spectra “formulation Option A for the Supercoatings PrimaryLayer from Example 3SA3 Color twoH, (Color 2HBrown)” showing the glassside of the dual layer, and the glass side of a single 3 mil Example 3Supercoatings Primary Layer drawdown. Again the spectra match up verywell.

These composite films are then suitable for typical testing related tothe properties desirable in Radiation curable Supercoatings intended foroptical fiber applications. Testing can include % RAU. This isespecially of value when the Secondary layer is being applied wet over awet Primary Coating Layer and it becomes critical that the cure rate ofthe Secondary layer is not faster than the cure rate of the PrimaryCoating layer because if the Secondary Coating cures faster than theprimary coating then the Primary Coating may never cure to its desired %RAU because the optical transmission of cured Secondary Coating Layer istypically less than that of liquid, uncured Secondary Coating Layer.

An interesting observation is that with this new Method of FormulatingRadiation curable Supercoatings for Optical Fiber it has been possibleto formulate Radiation curable Supercoatings with the following enhancedfunctional Properties:

A % RAU that ranges now to an upper limit of about 100% for both thePrimary Coating Layer and the Secondary Coating Layer.

This method permits the investigation of the properties of primary andsecondary as a composite Supercoatings film in ways not available in thepast. With this method it is now possible to conduct feasibility studiesof Supercoatings Candidate Secondary Layers over Supercoatings CandidatePrimary Layers for tensile properties, DMA characteristics,environmental durability, etc., with easily handled films instead ofhaving to use the Draw Tower Simulator. There are many understoodbenefits of using the Multi-layer Film Drawdown method, including, butnot limited to the following: the film drawdown takes away the linespeed as a factor in coatings functionality to allow for more basicanalysis; it also allows the formulator to evaluate the migration ofmaterials from layer to layer during the wet on dry and wet on wetprocessing steps.

Another advantage of the Multi-Layer Film Drawdown method is that it iscritical for both wet on wet processing and wet on dry processing thatsufficient through cure is possible to cure the primary coating to therequisite percentage RAU when the coating is applied to wire or opticalfiber. In practice, it is known that in Wet on dry processing, theprimary coating may be undercured to achieve line speed with theexpectations that the cure will be finished in the primary coating whenthe radiation is applied to the secondary coating. Therefore use of theMulti-Layer Film Drawdown method is helpful to simulate wet on wetapplication as compared to wet on dry application and testing the % RAUto determination of cure of primary through the secondary. Thesimulation allows the formulator to quickly evaluate the efficacy ofdifferent photoinitiators. This testing has already led to thehypothesis that for Radiation Curable Supercoatings for Optical Fiber,to achieve the very high levels of % RAU that are desired and required,it is believed, without intending to be bound thereby, to be better tohave a different chemical type of photoinitiator in the SecondaryCoating layer than in the Primary Coating layer.

In this way, there will be two different photo initiated reactionstaking place in the layers, rather than having one photoinitiator try toachieve the desired level of cure in both layers.

Another benefit of the Multi-layer film drawdown method is approximatingthe composite behavior of the cured secondary coating layer over thecured primary coating that can be correlated with Primary and Secondarycharacteristics that can be defined in SUPERCOATINGS. It is possible toevaluate the functional properties of each coating layer by analyzingfilm using solid film theology testing, otherwise known as DMA (dynamicMechanical Analysis)

The conclusion is that there is very little intermixing during the dualdrawdown process, and that the method is useful in evaluating candidatesfor Supercoatings Primary Coating Layers and Supercoatings SecondaryCoating Layers.

The following examples further illustrate the invention but, of course,should not be construed as in any way limiting its scope.

EXAMPLES

The ingredients listed in these Examples have the following commercialnames, are available from the listed source and have the indicatedchemical composition.

Commercial Name Supplier Description Ebecryl 3700 Cytec Bisphenol Adiglycidylether diacrylate Celloxide 2021P Daicel ChemicalCycloaliphatic epoxy Eponex 1510 Hexion Hydrogenated bisphenol Adiglycidylether OXT-101 Toagosei 3-ethyl-3-hydroxymethyl-oxetane SR 492Sartomer Propoxylated trimethylolpropane triacrylate Pluracol GP430 BASFPropoxylated glycerol (polyether triol) Silwet L-7600 MomentivePolyalkyleneoxide modified polydimethylsiloxane BYK-A-501 BYK-Chemiesilicone-free solution of foam destroying polymers Irganox 1035 CibaHindered phenol antioxidant PRINT Blue 15DT7083 The Flint GroupPhthalocyanine Blue pigment Hostaperm Violet RL, Clariant CarbozoleViolet pigment Pigment Violet 23 IRGACURE 184 Ciba 1-hydroxycyclohexylphenyl ketone, free radical photoinitiator Chivacure-1176 Chitec mixtureof triarylsulfonium hexafluoroantimonate salts, cationic photoinitiatorBR-543 Bomar Specialties Aliphatic urethane diacrylate oligomer SR 344Sartomer Polyethylene glycol (400) diacrylate (MW 508) SR 504D SartomerEthoxylated(4) Nonylphenol acrylate (MW 450) SR 531 Sartomer Cyclictrimethylolpropane formal acrylate (MW 200) SR 395 Sartomer Isodecylacrylate (MW 192) Irgacure 651 Cibaα,α-dimethoxy-alpha-phenylacetophenone free radical photoinitiator VinylCaprolactam BASF Vinyl amide

Abbreviation Meaning BHT 2,6-di-tert-butyl-4-methylphenol, availablefrom Fitz Chem. CN-120Z epoxy diacrylate, available from Sartomer. DABCO1,4-diazabicyclo[2.2.2]octane, available from Air Products. DBTDLdibutyl tin dilaurate, available from OMG Americas. HEA hydroxyethylacrylate, available from BASF HHPA hexahydrophthalic anhydride,available from Milliken Chemical. SR-506 isobornyl Acrylate, availableas from Sartomer. Photomer 4066 ethoxylated nonylphenol acrylate,available from Cognis. Pluracol 1010 polypropylene glycol (MW = 1000),available from BASF; SR-306HP tripropylene glycol diacrylate (TPGDA),available from Sartomer. SR-349 ethoxylated bisphenol A diacrylate,available from Sartomer. Mondur ® TDS Grade II Monomeric toluenediisocyanate (TDI); a high 2,4-isomer TDI; NCO weight 48%, viscosity 3mPa · s@25° C., equivalent weight 87.5; functionality 2; available fromBayer TDI An 80/20 blend of the 2,4- and 2,6-isomer of toluenediisocyanate, available from BASF IPDI Isophorone diisocyanate,available from Bayer TPO 2,4,6-trimethylbenzoyldiphenylphosphine oxidetype photoinitiator, available from Chitech.

The present invention is further illustrated with a number of examples.

In all of these examples, the process is as follows:

-   -   Step One: determining the maximum Acceptable Increase in        Attenuation requirements for the telecommunications network        where the optical fiber will be installed;    -   Step Two: determining the Field Application Environment of the        Supercoatings by understanding the:        -   i) type of glass being used in the optical fiber;        -   ii) whether the Supercoatings Secondary Layer will be            applied over the Supercoatings Primary Layer wet on dry or            wet on wet;        -   iii) the type, number of lights and positioning of lights            along the draw tower manufacturing line that are used to            cure the Supercoatings on the optical fiber; and        -   iv) the line speed at which the Supercoatings will be            applied;    -   Step Three: using a Three-Dimensional Laced Methodology of        -   i) Evaluation of candidate Radiation curable Supercoatings            by evaluation of the Radiation curable Supercoatings Primary            Layer and Secondary Layer for the Six defined Radiation            curable Supercoatings parameters;        -   ii) Testing the Radiation curable Supercoatings Primary            Layer and the Secondary Layer to determine if the required            functional property(s) of Supercoatings are achieved;            -   wherein if the required functional property of                Supercoatings has not been achieved, reformulating            -   either or both of the Primary or Secondary coating;        -   iii) testing the reformulated Primary or Secondary Coating            to determine if the desired functional property is achieved;            -   wherein if the desired functional property is achieved                then proceeding to step d);            -   wherein if the desired functional property is not                achieved, then repeat steps ii) and iii) until the            -   desired functional property is achieved; and then    -   Step Four: integrating the effects of reformulation of the        Supercoatings Primary Coating Layer and the Supercoatings        Secondary Coating Layer by evaluating the change in the        formulation relative to all the other defined functional        property requirements of Supercoatings; and    -   Step Five: using the results from the Three-Dimensional Laced        Methodology to finalize the selection of Supercoatings to        provide the properties required to achieve the Maximum        Acceptable Increase in Attenuation of the coated optical fiber.

Example 1 Request for Supercoatiags for Microbeading Resistant SingleMode Optical Fiber

An optical fiber manufacturer wishes to apply a radiation curableSupercoatings to their Single Mode Optical Fiber.

The glass used in this Single Mode Optical Fiber is of the most moderntype, able to resist Microbending.

Step One:

The requested Microbending Sensitivity for optical fiber used in thisnetwork is reported at:

dB/Km of less than about 0.06 at 1310 nm and −60° C.;

dB/Km of less than about 0.11 at 1550 nm and −60° C.; and

dB/Km of less than about 0.15 at 1625 nm and −60° C.

Step Two

Commercial Fiber Data

The radiation curable Radiation curable Supercoatings is applied Wet onDry.

The curing lights available are: 600w/10 inch D Lamps.

The number of curing lights are: 2 in the primary area and 4 after thesecondary coating is applied-possibly up to 5 if needed.

The line speed at which the Supercoatings will be applied is about 1400m/minute.

Step Three-Formulating Supercoatings

Four different formulators are given the task of working on potentialPrimary Coating Layers for this radiation curable Supercoatings.

Each Primary Coating Formulator selects the raw materials for theirstarting Oligomer, then the photoinitiator(s), antioxidant, one or morediluent monomers and other additives based on information available. Ingeneral, without intending to be bound thereby, the oligomer synthesisis carried out as follows:

Oligomers suitable for coating compositions of the invention areprepared by reaction of at least one polyether polyol, at least onediisocyanate, at least one hydroxyl terminated acrylate or(meth)acrylate, and optionally an alcohol. The following oligomersynthesis methods illustrate two different methods for synthesizing theoligomer. However, it will be appreciated by the skilled artisan thatother synthesis methods also can be used so long as the oligomercomprises a urethane-backbone, with at least one terminal unsaturatedgroup such as an alkenyl group or vinyl group.

Oligomer Synthesis—Method A is also known as an “outside-in” method thatfirst reacts the isocyanate with hydroxyl terminated acrylate ormethacrylate, followed by the reaction with polyol.

To a mixture of diisocyanate and inhibitor, HEA is added in a controlledmanner so that the temperature does not exceed 40° C. The mixture isallowed to react at 40° C. for 2 h so that the desired NCO content isreached. Polyol and catalyst are then added, and the mixture is allowedto react at 80° C. for 2 h or longer, until the NCO content is notgreater than 0.10.

Oligomer Synthesis—Method B is also known as an “inside-out” method thatfirst reacts the isocyanate with polyol, followed by the reaction withhydroxyl terminated acrylate or methacrylate.

Catalyst is added to a mixture of diisocyanate, polyol and inhibitor.The mixture is allowed to react at 60° C. for 2 h, so that the desiredNCO content is reached. Then, HEA is added, and the mixture is allowedto react at 85° C. for 1 h or longer, until the NCO content is notgreater than 0.05.

Polyether polyols suitable for preparing oligomers in accordance withthe invention preferably are selected from the group consisting of apolyethylene glycol and a polypropylene glycol. In an embodiment, thepolyether polyol is a polypropylene glycol.

Catalysts for synthesizing urethane based oligomers for use in radiationcurable coatings for optical fiber are known in the art. The catalyst isselected from the group consisting of copper naphthenate, cobaltnaphthenate, zinc naphthenate, triethylamine, triethylenediamine,2-methyltriethyleneamine, dibutyl tin dilaurate (DBTDL); metalcarboxylates, including, but not limited to: organobismuth catalystssuch as bismuth neodecanoate, CAS 34364-26-6; zinc neodecanoete, CAS27253-29-8; zirconium neodecanoate, CAS 39049-04-2; and zinc2-ethylhexanoate, CAS 136.53-8; sulfonic acids, including but notlimited to dodecylbenzene sulfonic acid, CAS 27176-87-0; and methanesulfonic acid, CAS 75-75-2; amino or organo-base catalysts, including,but not limited to: 1,2-dimethylimidazole, CAS 1739-84-0; anddiazabicyclo[2.2.2]octane (DABCO), CAS 280-57-9 (strong base); andtriphenyl phosphine; alkoxides of zirconium and titanium, including, butnot limited to zirconium butoxide, (tetrabutyl zirconate) CAS 1071-76-7;and titanium butoxide, (tetrabutyl titanate) CAS 5593-70-4; and ionicliquid phosphonium, imidazolium, and pyridinium salts, such as, but notlimited to, trihexyl(tetradecyl)phosphonium hexafluorophosphate, CAS No.374683-44-0; 1-butyl-3-methylimidazolium acetate, CAS No. 284049-75-8;and N-butyl-4-methylpyridinium chloride, CAS No. 125652-55-3; andtetradecyl(trihexyl) phosphonium.

All of these catalysts are commercially available.

In an embodiment, the catalyst is DBTDL or is an organobismuth catalystsuch as “COSCAT 83” proprietary organobismuth catalyst, available fromCosChem.

The choice of Photoinitiator is determined by:

-   -   1) the radiation source, intensity, proximity to the coating    -   2) the coating layer thickness,    -   3) whether the formulation is clear or whether the formulation        contains pigments, and if “pigment-containing” the type of        pigment and the amount of pigment present in the formulation.    -   4) the types of oligomers present in the composition    -   5) whether the coating composition is the Primary or Secondary        coating layer, and whether the Secondary Coating Layer is        applied wet-on-wet or wet-on-dry.

There are two general classes of photoinitiators:

-   Type I: photoinitiators undergo a uni-molecular bond cleavage upon    irradiation to yield free radicals-   Type II: photoinitiators undergo a bimolecular reaction where the    excited state of the photoinitiator interacts with a second molecule    (a co-initiator) to generate free radicals.

UV photoinitiators of both Type I and Type II are available.

Two different formulators are given the task of working on potentialSecondary Coating Layers for this radiation curable Supercoatings.

Each Secondary Coating Formulator selects the raw materials for theirstarting Oligomer, then the photoinitiator(s), antioxidant, one or morediluent monomers and other additives based on information available.

In selecting their raw materials, each Secondary Coating Formulatortakes into account the following: TDI Type II is inexpensive, and is afast reacting isocyanate. Further to the selection of TDI Type II foruse in Secondary Coatings, group contribution theory (takes thecharacteristics of each part of the group and contributes) teaches thatthe aromatic group in the isocyanate contributes to high Tg and highmodulus in the secondary, which is a technical reason why aromaticisocyanates would be favored for secondary coatings.

BHT Food Grade: Antioxidant scavenges free radicals (which is importantbecause HEA (inhibited by methyl hydroquinone) can self-polymerize);therefore a synthetic chemist plans the synthesis to have the BHT in thereaction mixture before the HEA The scavenging reaction also requiresthe presence of oxygen-it is known that the oxygen in normal ambient airis typically sufficient for this purpose.

2-HEA (2-hydroxy ethyl acrylate) is a simple acrylate which historicallyhas yielded very good cure rates in formulated radiation curablecoatings for optical fiber. HBA (hydroxy butyl acrylate) or HPA(hydroxyl ethyl acrylate) are known to be not as reactive in thesynthesis.

Both the Primary Coating Formulators and the Secondary CoatingFormulators are aware of the following as they formulate; thepolymerization of the secondary coating layer causes shrinkage of thatlayer and the shrinkage of the secondary coating layer puts pressure onthe primary coating layer, whether the primary coating layer is alreadycured or is in the process of being cured when the secondary coatinglayer is being cured. Stress relaxation is a measure of the relief ofstress on the primary caused by the shrinkage of the secondary coatingas the secondary coating polymerizes. The temperature of thepolymerization of the Secondary Coating Layer of a Supercoating has tobe above the Tg for fast relief of that shrinkage. In formulatingradiation Curable Supercoatings for Optical Fiber, it is assumed thatthe temperature of the polymerization of both the Primary and Secondarycoating layer is well above their Tg's. If the polymerizationtemperature is below Tg, the stress relaxation is not as fast. If stressrelaxation does not timely occur, the stress on the optical fiber canlead to unacceptable attenuation.

Wet on Wet processing has the potential for additional stress relaxationissues only because the fiber is being coated with two liquids beforeany polymerization occurs and both liquids are potentially cooler thanthe fiber, then there will be simultaneous polymerization taking placewith dual heats of polymerization so as the curing takes place thetemperature profile is uneven between the coating layers. Again, theformulators have to be aware of the fact that with the polymerizationtaking place simultaneously the difference in cross-link density is alsoa huge factor as there is much less cross-link-density in the primarycoating as there is the secondary.

In the field of optical fiber manufacture it is known that the fibercabler desires that the optical fiber is in a relaxed state before theoptical fiber is manipulated further during the cabling process.

Thus, all formulators have to be aware that minimizing stress relaxationissues is critical, otherwise, the cabling operation will take longer asthe cabler has to wait longer after the coatings are applied to theoptical fiber to cable the optical fiber to allow for more stressrelaxation to occur. It is known if the formulators misformulate suchthat the primary coating layer and the secondary coating layer don'trelax properly and timely, it will be very, very difficult for thecabled optical fiber to not exceed the you never achieve the MaximumAcceptable lucrease in Attenuation.

To enhance stress relaxation the formulators select materials that aremore flexible in the secondary coating; however, these flexiblematerials must be selected in such a way that the additional flexibilitydoes not negatively interfere with targeted physical properties of highTg and high strength.

Examples 1-4

These Examples illustrate Formulator Alpha's candidate formulations forthe candidate Primary Coating Layer of the Supercoatings.

Example Example Example Example 1PA1 1PA2 1PA3 1PA4 Material Descriptionwt. % wt. % wt. % wt. % Oligomer ACCLAIM polyol 4200 53.03 51.68 53.0353.03 2,6-di-tert-butyl-p-cresol 0.09 0.09 0.09 0.09 IPDI 4.73 4.76 4.734.73 dibutyl tin dilaurate 0.03 0.03 0.0 0.03 zinc neodecanoate 0.0 0.00.03 0.0 dodecylbenzene sulfonic 0.0 0.0 0.00 0.0 acid 2-HEA 1.72 1.941.72 1.72 Total Oligomer wt. % 59.60 58.50 59.60 59.60 IRGACURE 819 1.501.50 1.50 2.00 IRGANOX 1035 0.60 0.60 0.60 0.60 TINUVIN 123 0.10 0.100.10 0.10 ethoxylated nonyl phenol 26.45 34.05 26.45 26.10 acrylate SR349D Monomer 1.50 1.00 1.50 1.50 SR 339C (PEA) 9.00 3.00 9.00 9.00THIOCURE TMPMP 0.75 0.75 0.75 0.6 A-189 0.50 0.50 0.50 0.50 Total (dueto rounding of 100.00 100.00 100.00 100.00 significant figures may be+/−0.10 wt. %)

Examples 1PB1-1PB4

These Examples illustrate Formulator Beta's candidate formulations forthe Primary Coating Layer of the Supercoatings

Example Example Example Example 1PB1 1PB2 1PB3 1B4 Material Descriptionwt. % wt. % wt. % wt. % Oligomer ACCLAIM polyol 4200 45.78 45.78 45.7845.78 acrylic acid, 99% 0.01 0.01 0.01 0.01 BHT 0.04 0.04 0.04 0.04Mondur TDS Grade II 2.92 2.92 2.92 2.92 dibutyltin dilaurate 0.0 0.00.02 0.02 zinc neodecanoate 0.02 0.0 0.0 0.0 dodecylbenzene 0.0 0.02 0.00.0 sulfonic acid 2-HEA 1.24 1.24 1.24 1.24 Total Oligomer wt. % 50.0150.01 50.01 50.01 IRGANOX 1035 0.50 0.50 0.50 0.50 SR-504D 46.29 46.2946.29 46.29 SR 349D 0.91 0.91 0.91 0.91 TINUVIN 123 0.10 0.10 0.10 0.10IRGACURE 819 1.20 1.20 1.20 0.0 TPO 0.0 0.0 0.0 1.20 A-189 0.99 0.990.99 0.99 Total (due to rounding of 100.00 100.00 100.00 100.00significant figures may be +/−0.10 wt. %)

Examples 1PC1 Through 1PC4

These Examples illustrate Formulator Gamma's candidate formulations forthe Primary Coating Layer of the Supercoatings.

Example Example Example Example 1PC1 1PC2 1PC3 1PC4 Material Descriptionwt. % wt. % wt. % wt. % Oligomer ACCLAIM polyol 4200 57.47 57.44 57.4457.18 BHT 0.1 0.1 0.1 0.1 IPDI 5.25 5.25 5.25 5.25 dibutyltin dilaurate0.03 0.03 0.03 0.03 zinc neodecanoate 0.0 0.03 0.0 0.15 dodecylbenzene0.0 0.0 0.03 0.15 sulfonic acid 2-HEA 2.15 2.15 2.15 2.14 Total Oligomerwt. % 65.00 65.00 65.00 65.00 SR-504D 21.55 21.55 21.55 21.55 SR 339C 99 9 9 SR 349D 1 1 1 1 IRGACURE 819 1.5 0.0 0.75 0.5 TPO 0.0 1.5 0.751.00 IRGANOX 1035 0.6 0.6 0.6 0.6 TINUVIN 123 0.1 0.1 0.1 0.1 A-189 1.251.25 1.25 1.25 Total (due to rounding of 100.00 100.00 100.00 100.00significant figures may be +/−0.10 wt. %)

Examples 2SA1-2SA5 illustrate Formulator Episilon's candidateformulations for the Secondary Coating Layer

Ex. Ex. Ex. Ex. Ex. Secondary 2SA1 2SA2 2SA3 2SA4 2SA5 MaterialDescription Wt. % Wt. % Wt. % Wt. % Wt. % Oligomer OligMT* 29.95Oligomer OligTT** 29.95 28.78 29.95 Oligomer OligWT*** 29.95 OligomerWt. % of 29.95 29.95 29.95 28.78 29.95 total formula CN110 39.85 39.8539.85 38.42 39.85 SR-506A 7.4 7.4 7.4 7.2 7.4 SR 339C(PEA) 8.4 8.4 8.48.15 8.4 SR 306F(TPGDA) 5.9 5.9 5.9 5.76 5.9 SR 238 MONOMER 4.5 4.5 4.54.27 4.5 CPI-6992 SARBOX SB520E35 2.43 TPO HP 1 1 1 Irgacure 819 1 0 11-Hydroxycyclohexyl- 2 2 2 3 2 Phenyl Ketone IRGANOX 1035 0.5 0.5 0.50.5 0.5 FF(W&C) DC-190 Surfactant 0.33 0.33 0.33 0.33 0.33 DC-57Additive 0.17 0.17 0.17 0.17 0.17 Total (due to rounding of 100 100 100100 100 significant figures may be +/−0.10 wt. %) *Oligomer **Oligomer***Oligomer OligMT OligTT OligWT TDI Type II 22.47 21.26 22.32 BHT FoodGrade 0.07 0.05 0.05 2-HEA 13.99 14.18 16.08 Dibutyltin Dilaurate 0.070.05 0.05 Pluracol P1010 63.41 64.46 61.50 Total (due to rounding of 100100 100 significant figures may be +/−0.10 wt. %)

Examples 2SB1-2SB4

These Examples illustrate Formulator Zeta's Candidate formulations forthe Secondary Coating Layer of the Supercoatings

Ex. Ex. Ex. Ex. Ex. Secondary 2SB1 2SB2 2SB3 2SB4 2SB5 Materialdescription Wt. % Wt. % Wt. % Wt. % Wt. % Oligomer OligMT* 30.00 24.60Oligomer OligTT** 30.00 27.80 Oligomer 30.00 OligWT*** Oligomer Wt. % of30.00 24.60 30.00 27.80 30.00 total formula CN120Z 40.00 45.40 40.0042.20 40.00 SR-506A 7.5 7.5 7.5 7.5 7.5 SR 339C 8.5 8.5 8.5 8.5 8.5 SR306F 6 6 6 6 6 SR 238 4.5 4.5 4.5 4.5 4.5 Irganox 1035 FF 0.5 0.5 0.50.5 0.5 Irgacure 819 0.0 0.0 0.0 0.0 0.0 TPO HP 0.5 0.5 0.5 0.5 0.5 1- 22 2 2 2 Hydroxycyclohexyl- Phenyl Ketone DC-190 Surfactant 0.33 0.330.33 0.33 0.33 DC-57 Additive 0.17 0.17 0.17 0.17 0.17 Total (due torounding of 100 100 100 100 100 significant figures may be +/−0.10 wt.%) *Oligomer **Oligomer ***Oligomer OligMT OligTT OligWT TDI Type II22.47 21.26 22.32 BHT Food Grade 0.07 0.05 0.05 2-HEA 13.99 14.18 16.08Dibutyltin Dilaurate 0.07 0.05 0.05 Pluracol P1010 63.41 64.46 61.50Total (due to rounding of 100 100 100 significant figures may be +/−0.10wt. %)

The results of the Multilayer Film Drawdown analysis show the mostcompatible potential combinations are:

1PA2 and 2SA4

1PA2 and 2SB3

1PB3 and 2SA4

1PB3 and 2SB3

1PC1 and 2SA4

1PC1 and 2SB3

1PD5 and 2SA4

1PD5 and 2SB3

These combinations are then run on the Draw Tower Simulator.

Certain combinations are found to achieve the properties of aSupercoating at some, but not all, of the line speeds between about 750m/min and about 2,100 m/min

These combinations are found to be Supercoatings at all line speeds:

wherein the composition of the Primary Coating layer, prior to curing,is selected from the group

consisting of the formulations of Examples 1PA2, 1PB3, 1PC1; and

wherein the composition of the Secondary Coating layer, prior to curing,is selected from the group

consisting of the formulations of Examples 2SA4 and 2SB3.

Example 2

An optical fiber manufacturer wishes to save energy costs by switchingat least part of their curing lights over to LED lights. They decide tostart the switch by changing their lights curing the primary coating toLED lights. Their current primary coating is Example 1PB3 (from Example1).

The Single Mode Optical Fiber is of the most modern type, able to resistMicrobending.

Step One:

The requested Microbending Sensitivity for single mode optical fiberused in this network is reported at:

dB/Km of less than about 0.02 at 1310 nm and −60° C.;

dB/Km of less than about 0.03 at 1550 nm and −60° C.; and

dB/Km of less than about 0.05 at 1625 nm and −60° C.

Step Two

The Single Mode Optical Fiber is of the most modern type, able to resistMicrobending

The radiation curable Radiation curable Supercoatings is applied Wet onDry.

The type of curing lights for the primary coating are: The optical fibermanufacturer wants the flexibility of working with any LED lamp at 395nm with a power of at least 4 W/cm².

For purposes of this Example, the LED Lamp chosen is a 8 W/cm² LED unitwith a peak emission at 395 nm. This type of LED lamp is available fromPhoseon as an RX Fireline LED unit.

The number of curing lights are: from 1 to 3 in the Primary Coatingsarea,

The type of curing lights for the secondary coating are: 600 w/10 inch DLamps

The number of curing lights: 3 in the Secondary Coatings Area

The line speed at which the Supercoatings will be applied isapproximately 1300 m/min.

Example Example 2Alpha 2Beta LED Curable LED Curable Version of Versionof LED Curable Primary Coatings Example 1PB3 Example 1PB3 ComponentsDescription wt. % wt. % {circumflex over ( )}Acclaim PPG 4200/TDI/HEAurethane acrylate oligomer 47.56 47.05 Ethoxylated bisphenol A monomer0.85 0.84 diacrylate Ethoxylated nonylphenol acrylate monomer 44.0943.62 Lucirin TPO-L 2,4,6-trimethylbenzoyl ethoxy 5.00 5.00 phenylphosphine oxide Irgacure 819 bis(2,4,6-trimethylbenzoyl)- 1.00 2.00phenylphosphineoxide Irganox 1035 hindered phenol antioxidant 0.47 0.47Bis-(1-octyloxy-2,2,6,6- 0.09 0.09 tetramethyl-4-piperidinyl) sebacatelight stabilizer A-189 γ-mercaptopropyl trimethoxy 0.94 0.93 silaneTotal (due to rounding of 100.00 100.00 significant figures may be+/−0.10 wt. %)

Ingredients in {circumflex over ( )}Acclaim PPG 4200/TDI/HEA OligomerWt. % ACCLAIM polyol 4200 91.54 acrylic acid, 99% 0.02 BHT 0.08 MondurTDS Grade II 5.83 dibutyltin dilaurate 0.05 2-HEA 2.48 Total (due torounding of significant 100.00 figures may be +/−0.10 wt. %)

Therefore the fourth aspect of the instant claimed invention is asingle-mode optical fiber coated with Supercoatings, wherein saidSupercoatings comprise,

-   -   Primary Coating Layer and a Secondary Coating Layer,    -   wherein the composition of the Primary Coating layer, prior to        curing, is selected from the group consisting of the        formulations of Examples 1PA2, 1PB3, 1PC1, 2Alpha, 2Beta; and        wherein the composition of the Secondary Coating layer, prior to        curing, is selected from the group consisting of the        formulations of Examples 2SA4 and 2SB3 and 5SA1.

Example 3

An optical fiber manufacturer—wishes to apply a radiation curableSupercoatings for their Single Mode Optical Fiber. The Single ModeOptical Fiber is of the most modern type, able to resist Microbending.

Step One:

The requested Microbending Sensitivity for single mode optical fiberused in this network is reported at:

dB/Km of less than about 0.02 at 1310 nm and −60° C.;

dB/Km of less than about 0.06 at 1550 nm and −60° C.; and

dB/Km of less than about 0.09 at 1625 nm and −60° C.

Step Two

The Single Mode Optical Fiber is of the most modern type, able to resistMicrobending

The radiation curable Radiation curable Supercoatings is applied Wet onWet.

The Secondary Coating is a Colored Secondary, wherein the clearSecondary Base Coat is mixed in line with a Color Concentrate.

The type of curing lights are: Proprietary Lamps with a metal halidespectrum similar to Fusion D lamps

The number of curing lights is: 3 lamps/20 inch.

The line speed at which the Supercoatings will be applied isapproximately 1700 meters/minute.

Step Three

Step Three-Formulating Supercoatings

For the Primary Coating Layer an Oligomer is selected, along with aphotoinitiator, antioxidant, two diluent monomers and other additivesbased on information available. For the Secondary Coating Layer anOligomer Blend is selected, along with a photoinitiator, antioxidant,two diluent monomers and other additives based on information availableto formulate a Clear Secondary Coating. Colorants are formulated to addto the Clear Secondary Coating during in-line mixing. In addition torunning the Primary coating and Secondary coating on the Draw towerSimulator operating at 1625 meters/minute, the Multilayer Film DrawDowntest method is used to create Supercoatings Film of a Primary CoatingLayer with an overcoat of Clear Secondary Coating Layer. The film isremoved from the substrate and tested for the properties inSupercoatings.

In addition to using the Multilayer Film DrawDown test method to createSupercoatings Film of a Primary Coating Layer with an overcoat of ClearSecondary Coating Layer, a Multilayer Film DrawDown is made of a PrimaryCoating Layer and a Colored Secondary made of the Clear SecondaryCoating and Colorant.

Example Example Example Example Candidate Primary 3PA1 3PA2 3PA3 3PA4Coatings Weight Weight Weight Weight Material description PercentPercent Percent Percent Acclaim polyol 4200 57.63 57.63 57.63 57.63 BHTFood Grade 0.1 0.1 0.1 0.1 IPDI 5.12 5.12 5.12 5.12 Dibutyltin Dilaurate0.03 0.03 0.03 0.03 zinc neodecanoate 0.03 0.15 dodecylbenzene 0.03 0.15sulfonic acid 2-HEA 2.12 2.09 2.09 1.82 Oligomer Wt. % 65.00 65.00 65.0065.00 of total formula SR-504D 21.55 21.55 21.55 21.55 SR 339C 9 9 9 9SR 349D Monomer 1 1 1 1 Irgacure 819 1.5 0.75 0.5 TPO 1.5 0.75 1 IRGANOX1035 0.6 0.6 0.6 0.6 FF(W&C) TINUVIN 123 0.1 0.1 0.1 0.1 A-189 1.25 1.251.25 1.25 Total (due to rounding 100 100 100 100 of significant figuresmay be +/−0.10 wt. %)

Example Example 3SA1 Example 3SA3 Clear 3SA2 Color oneH Color oneH twoHCandidate Secondary Coating Clear Rose Rose Brown Brown with OptionalColor Secondary Concentrate Added Coating Concentrate SecondaryConcentrate Secondary Weight Weight Weight Weight percent percentpercent percent Clear Base M^(†) 100.00 90.64 75 84.4 75 White 6.8 Red1.6 6.8 Yellow 8 Orange 0.96 Black 0.8 Rose colored 2° inter. 25 Browncolored 2° inter. 25 Total (due to rounding of significant 100 100 100100 figures may be +/−0.10 wt. %)

Clear Base M^(†) Ingredients Weight % Oligomer M3^(∴) 20.27 CN120Z 50.00TPO 1.06 Chivacure 184 0.80 BHT Food Grade 0.50 KIP 100 F 1.06 SR306MONOMER 15.00 SR 238 MONOMER 9.80 SR-504D 0.50 DC-190 Surfactant 0.68DC-57 Additive 0.33 Total (due to rounding of significant 100.00 figuresmay be +/−0.10 wt. %)

Example 3 Continued

Oligomer M3^(∴) is an Oligomer. The ingredients combined to makeOligomer M3 include the following:

Oligomer M3^(∴) Material description Wt. % TDI Type II 21.26 BHT FoodGrade 0.05 2-HEA 14.18 Dibutyltin Dilaurate 0.05 Pluracol P1010 64.46Total (due to rounding of significant 100.00 figures may be +/−0.10 wt.%)

Example Example Example 3SA1 3SA2 3SA3 Clear Color Color oneH oneH twoHCandidate Secondary Coating Clear Rose Rose Brown Brown with OptionalColor Secondary Concentrate Added Coating FILTER TYPE ConcentrateSecondary Concentrate Secondary Total Base 2° Resin: 100.00 97.66 84.4096.10 ⁺Total Colorant: 9.36 2.34 15.60 3.90 ^(@)Total Dry Pigment: 4.591.15 3.12 0.78 *Photoinitiator %: 2.92 2.65 2.85 2.46 2.81

Example 4

An optical fiber manufacturer wishes to apply a radiation curableSupercoatings for their MULTI-Mode Optical Fiber. The MULTI-Mode OpticalFiber is of the most modern type, able to resist Microbending.

Step One:

The requested Microbending Sensitivity for single mode optical fiberused in this network is as of this writing, still under investigation at850 nm and 1300 nm. As details develop more Microbending Sensitivitytesting will be done.

Step Two

The MULTI-Mode Optical Fiber is of the most modern type, able to resistMicrobending

The radiation curable Secondary Coating is applied Wet on Wet PrimaryCoating.

The line speed at which the Primary Coating and Secondary Coating willbe applied is about 200 meters/minute.

The Secondary Coating is a Clear Secondary.

The type of curing lights are 600 w/D Lamps.

The number of curing lights are: 3 in the Primary Coatings area. 3 inthe Secondary Coatings Area

Step 3.

For the Primary Coating Layer an Oligomer is selected, along with aphotoinitiator, antioxidant, two diluent monomers and other additivesbased on information available to make a Multi-Mode Coating. For theSecondary Coating Layer an Oligomer Blend is selected, along with aphotoinitiator, antioxidant, two diluent monomers and other additivesbased on information available to formulate a Clear Secondary Coatingfor Multi-Mode Coating.

Example 4PD1-4PD5

These Examples illustrate Formulator Delta's formulations for thePrimary Coating Layer

Ex. Ex. Ex. Ex. Ex. 4PD1 4PD2 4PD3 4PD4 4PD5 Material Description wt. %wt. % wt. % wt. % wt. % Oligomer 2,4-TDI 3.6 3.43 4.34 3.53 3.382,6-di-tert-butyl-p-cresol 0.05 0.05 0.04 0.05 0.05 acrylic acid 0.010.01 0.02 0.01 0.01 2-HEA 1.48 1.48 1.48 1.3 1.46 ACCLAIM polyol 420050.41 50.10 50.00 48.17 50.10 dibutyl tin dilaurate 0.03 0.03 0.03 0.030.03 Total Oligomer wt. % 55.58 55.91 55.91 53.09 55.91 ethoxylatednonyl 40.29 40.29 40.29 42.71 40.29 phenol acrylate SR 349D 1.2 1.501.50 1.7 1.50 TPO 0.9 0.0 1.60 1.7 1.70 IRGACURE ® 819 0.5 1.70 0.5IRGANOX 1035 1.5 0.50 0.50 0.3 0.50 TINUVIN 123 0.03 0.10 0.10 0.1 0.10A-189 0.90 0.9 0.80 0.90 0.90 Total (due to rounding of 100.00 100.00100.00 100.00 100.00 significant figures may be +/−0.10 wt. %)

The fifth aspect of the instant claimed invention is a multi-modeoptical fiber coated with radiation

curable coatings comprising a Primary Coating Layer and a SecondaryCoating Layer

wherein the composition of the Primary Coating layer, prior to curing,is selected from the group

consisting of the formulation of Example 4PD5; and

wherein the composition of the Secondary Coating layer, prior to curing,is selected from the group

consisting of the formulations of Examples 2SA4 and 2SB3.

Example 5

This Supercoatings Secondary is formulated from an existingSupercoatings Secondary to meet the needs of a customer that isrequesting a product with a higher refractive index to enable them touse installed equipment to ascertain concentricity in their finishedcoated fiber. The changes from the earlier coating are as follows:

a) include the use of SR-601 at about a 10% level,

b) the use of slightly more TPO, from 0.5% to 0.75%,

c) slightly more Chivacure 184, from 2% to 2.5%,

d) the elimination of IBOA and SR-306, which is replaced by about 15% ofPEA.

Example Example Example 5SA1 5SA2 5SA3 Function in Wt. % in Wt. % in Wt.% in Formula COMPONENT formula formula formula oligomer Oligomer M3^(∴)28.1 25.1 35.0 epoxy acrylate CN-110 37.4 39.4 37.4 acrylate monomerHDDA 5.2 5.2 5.2 acrylate monomer SR-601 10.3 10.3 10.3 acrylate monomerPEA 14.75 15.75 7.85 Photo initator TPO 0.75 0.75 0.75 Photo initiatorChivacure 184 2.5 2.5 2.5 Stabilizer Irgacure 1035 0.5 0.5 0.5 siliconsurfactant DC-190 0.33 0.33 0.33 Silicon Surfactant DC-57 0.17 0.17 0.17Total (due to 100 100 100 rounding of significant figures may be +/−0.10wt. %)

Oligomer M3^(∴) is an Oligomer. The ingredients combined to makeOligomer M3 include the following:

Oligomer M3^(∴) Material description Wt. % TDI Type II 21.26 BHT FoodGrade 0.05 2-HEA 14.18 Dibutyltin Dilaurate 0.05 Pluracol P1010 64.46Total (due to rounding of significant 100.00 figures may be +/−0.10 wt.%)

Example 6

This shows the combination of Primary Coating and Secondary Coating ineach of the listed Supercoatings.

Secondary Coating Primary Example Example Example Coating 2SA4 Example2SB3 3SA1 5SA1 Exam- Super- Supercoatings Supercoating Supercoatings plecoatings 013128 112057 081556 1PA2 072727 Exam- Super- SupercoatingsSupercoatings Supercoatings ple coatings 062551 062752 072054 1PB3041656 Exam- Super- Supercoatings Supercoatings Supercoatings plecoatings 062551100510 062752100510 072054100510 1PC1 0416100510 Exam-Super- Supercoatings Supercoatings Supercoatings ple coatings 013110112010 081510 2 Alpha 072710 Exam- Super- Supercoatings SupercoatingsSupercoatings ple coatings 062510 062710 072010 2 Beta 041610

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. Recitation of ranges of valuesherein are merely intended to serve as a shorthand method of referringindividually to each separate value falling within the range, unlessotherwise indicated herein, and each separate value is incorporated intothe specification as if it were individually recited herein. All methodsdescribed herein can be performed in any suitable order unless otherwiseindicated herein or otherwise clearly contradicted by context. The useof any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate the inventionand does not pose a limitation on the scope of the invention unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element as essential to the practice ofthe invention.

An embodiment embodiments of this invention are described herein,including the best mode known to the inventors for carrying out theinvention. Variations of those an embodiment embodiments may becomeapparent to those of ordinary skill in the art upon reading theforegoing description. The inventors expect skilled artisans to employsuch variations as appropriate, and the inventors intend for theinvention to be practiced otherwise than as specifically describedherein. Accordingly, this invention includes all modifications andequivalents of the subject matter recited in the claims appended heretoas permitted by applicable law. Moreover, any combination of theabove-described elements in all possible variations thereof isencompassed by the invention unless otherwise indicated herein orotherwise clearly contradicted by context.

The invention claimed is:
 1. A method of making a multi-mode opticalfiber that has a primary coating layer that is in contact with the outersurface of the optical fiber and a secondary coating layer that is incontact with the outer surface of the primary coating layer, the methodcomprising the steps of: forming the primary coating layer by curing acomposition comprising: 55.91 wt. % of an oligomer prepared by reactionof: 3.38 wt. % of 2,4-toluene diisocyanate, 0.05 wt. % of2,6-di-tert-butyl-p-cresol, 0.01 wt. % of acrylic acid, 1.46 wt. % of2-hydroxyethyl acrylate, 50.10 wt. % of polypropylene glycol, MW=4200,and 0.03 wt. % of dibutyltin dilaurate; 40.29 wt. % ethoxylated nonylphenol acrylate; 1.50 wt. % of bisphenol A ethoxylate diacrylate; 1.70wt. % of 2,4,6-trimethylbenzoyldiphenylphosphine oxide typephotoinitiator; 0.50 wt. % of hindered phenol antioxidant; 0.10 wt. % ofbis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate; and 0.90 wt. %of γ-mercaptopropyltrimethoxysilane; and forming the secondary coatinglayer by curing a composition selected from the group of formulacompositions (a), (b), (c) and (d) that are defined as follows: (a)28.78 wt. % of an oligomer prepared by reaction of: 21.26 wt. %, byweight of the oligomer, of an 80/20 blend of the 2,4- and 2,6-isomer oftoluene diisocyanate, 0.05 wt. %, by weight of the oligomer, of2,6-di-tert-butyl-4-methylphenol, 14.18 wt. %, by weight of theoligomer, of 2-hydroxyethyl acrylate, 0.05 wt. %, by weight of theoligomer, of dibutyltin dilaurate, and 64.46 wt. %, by weight of theoligomer, of polypropylene glycol, MW=1000; 38.42 wt. % of difunctionalbisphenol A-based epoxy acrylate oligomer; 7.2 wt. % of isobornylacrylate; 8.15 wt. % of 2-phenoxyethyl acrylate; 5.76 wt. % oftripropylene glycol diacrylate; 4.27 wt. % of 1,6-hexanediol diacrylate;2.43 wt. % of a blend, wherein said blend consists essentially of 35 wt.% of aromatic acid acrylate half ester and 65 wt. % of ethoxylatedtrimethylolpropane triacrylate; 1 wt. % of2,4,6-trimethylbenzoyldiphenylphosphine oxide type photoinitiator; 3 wt.% of 1-hydroxycyclohexyl-phenyl ketone; 0.5 wt. % of hindered phenolantioxidant; 0.33 wt. % of a blend, wherein said blend consistsessentially of, 40 to 70 wt. % of dimethyl, methyl(propyl(poly(ethyleneoxide) (propylene oxide))acetate)siloxane, 30 to 60 wt. % ofpoly(ethylene oxide propylene oxide) monoallyl ether acetate, and lessthan 9 wt. % of polyether polyol acetate; and 0.17 wt. % of dimethyl,methyl(propyl(poly(ethylene oxide))acetate) siloxane; (b) 30.00 wt. % ofan oligomer prepared by reaction of 21.26 wt. %, by weight of theoligomer, of an 80/20 blend of the 2,4- and 2,6- isomer of toluenediisocyanate, 0.05 wt. %, by weight of the oligomer, of2,6-di-tert-butyl-4-methylphenol, 14.18 wt. %, by weight of theoligomer, of 2-hydroxyethyl acrylate, 0.05 wt. %, by weight of theoligomer, of dibutyltin dilaurate, and 64.46 wt. %, by weight of theoligomer, of polypropylene glycol, MW=1000; 40.00 wt. % of epoxydiacrylate; 7.5 wt. % of isobornyl acrylate; 8.5 wt. % of 2-phenoxyethylacrylate; 6 wt. % of tripropylene glycol diacrylate; 4.5 wt. % of1,6-hexanediol diacrylate; 0.5 wt. % of hindered phenol antioxidant; 0.5wt. % of 2,4,6-trimethylbenzoyldiphenylphosphine oxide typephotoinitiator; 2 wt. % of 1-hydroxycyclohexyl-phenyl ketone; 0.33 wt. %of a blend, wherein said blend consists essentially of, 40 to 70 wt. %of dimethyl, methyl(propyl(poly(ethylene oxide) (propyleneoxide))acetate)siloxane, 30 to 60 wt. % of poly(ethylene oxide propyleneoxide) monoallyl ether acetate, and less than 9 wt. % of polyetherpolyol acetate; and 0.17 wt. % of dimethyl, methyl(propyl(poly(ethyleneoxide))acetate) siloxane; (c) 20.27 wt. % of an oligomer prepared byreaction of: 21.26 wt. %, by weight of the oligomer, of an 80/20 blendof the 2,4- and 2,6-isomer of toluene diisocyanate, 0.05 wt. %, byweight of the oligomer, of 2,6-di-tert-butyl-4-methylphenol, 14.18 wt.%, by weight of the oligomer, of 2-hydroxyethyl acrylate, 0.05 wt. %, byweight of the oligomer, of dibutyltin dilaurate, and 64.46 wt. %, byweight of the oligomer, of polypropylene glycol, MW=1000; 50.00 wt. % ofepoxy diacrylate; 1.06 wt. % of 2,4,6-trimethylbenzoyldiphenylphosphineoxide type photoinitiator; 0.80 wt. % of 1-hydroxycyclohexyl phenylketone; 0.50 wt. % of 2,6-di-tert-butyl-4-methylphenol; 1.06 wt. % of ablend, wherein said blend consists essentially of, 70 wt. % ofoligo[2-hydroxy-2-methyl- 1-[4(1-methyl-vinyl)phenyl]propanone] and 30wt. % of 2- hydroxy- 2- methyl- 1-phenylpropanone; 15.00 wt. % oftripropylene glycol diacrylate; 9.80 wt. % of 1,6-hexanediol diacrylate;0.50 wt. % of ethoxylated(4) nonyl phenol acrylate, MW=450; 0.68 wt. %of a blend, wherein said blend consists essentially of, 40 to 70 wt. %of dimethyl, methyl(propyl(poly(ethylene oxide) (propyleneoxide))acetate)siloxane, 30 to 60 wt. % of poly(ethylene oxide propyleneoxide) monoallyl ether acetate, and less than 9 wt. % of polyetherpolyol acetate; and 0.33 wt. % of dimethyl, methyl(propyl(poly(ethyleneoxide))acetate) siloxane; and (d) 28.1 wt. % of an oligomer prepared byreaction of: 21.26 wt. %, by weight of the oligomer, of an 80/20 blendof the 2,4- and 2,6-isomer of toluene diisocyanate, 0.05 wt. %, byweight of the oligomer, of 2,6-di-tert-butyl-4-methylphenol, 14.18 wt.%, by weight of the oligomer, of 2-hydroxyethyl acrylate, 0.05 wt. %, byweight of the oligomer, of dibutyltin dilaurate, and 64.46 wt. %, byweight of the oligomer, of polypropylene glycol, MW=1000; 37.4 wt. % ofa difunctional bisphenol A-based epoxy acrylate oligomer; 5.2 wt. % of1,6-hexanediol diacrylate; 10.3 wt. % of ethoxylated 4 bisphenol Adiacrylate; 14.75 wt. % of 2-phenoxyethyl acrylate; 0.75 wt. % of2,4,6-trimethylbenzoyldiphenylphosphine oxide type photoinitiator; 2.5wt. % of 1-hydroxcyclohexyl phenyl ketone; 0.5 wt. % of hindered phenolantioxidant; 0.33 wt. % of a blend of 40 to 70 wt. % of dimethyl,methyl(propyl(poly(ethylene oxide) (propylene oxide))acetate)siloxane,30 to 60 wt. % of poly(ethylene oxide propylene oxide) monoallyl etheracetate, and less than 9 wt. % of polyether polyol acetate; and 0.17 wt.% of dimethyl, methyl(propyl(poly(ethylene oxide))acetate) siloxane.